Chocolate Zucchini Cake

Super moist and indulgent chocolate zucchini cake is studded with chocolate chips and topped with chocolate fudge frosting. Made with three cups of shredded zucchini (you can’t taste it!), this is the most decadent way to eat your greens.

slice of chocolate zucchini cake on a black plate

Today, we have a triple dose of chocolate in the form of luxuriously rich chocolate zucchini cake. No, you can’t taste the zucchini. No, you can’t see the zucchini. Yes, it’s unbelievably delicious and I’m showing you exactly how to make it!

Chocolate Zucchini Cake Video Tutorial

Can you just look at how rich and moist this cake is? It tastes even better than it looks, I swear. The real secret behind it are the hidden vegetables inside. If you’re one who believes veggies should have nothing to do with dessert, keep an open mind. Carrot cake, anyone?!

slice of chocolate zucchini cake on a black plate with a fork

Why You’ll Love This Chocolate Zucchini Cake

  • Just as loved as my chocolate cake
  • Super moist and rich with mega chocolate flavor
  • Easy to make
  • Uses up summer zucchini
  • 3 cups of vegetables hiding inside– you don’t even taste it!
  • Covered in chocolate buttercream

Overview: Chocolate Zucchini Cake Ingredients

This decadent cake is made with fresh summer zucchini and pantry basics. Did you know that cocoa powder can dry out baked goods much more than flour? To compensate for this, we ensure there’s plenty of added moisture in the cake batter. Let’s review:

  • Flour: Sturdy all-purpose flour is the base of this cake recipe. Do not use cake flour– when combined with ultra-light cocoa powder, cake flour is too fine.
  • Unsweetened Natural Cocoa Powder: Cocoa powder takes the place of some flour. Just as in my regular chocolate cake recipe, make sure you’re using natural unsweetened cocoa powder instead of dutch-process cocoa powder. If you’re interested, see dutch-process vs natural cocoa powder for an in-depth explanation.
  • Baking Soda & Baking Powder: Use both baking soda and baking powder for lift.
  • Espresso Powder: Espresso powder accentuates the chocolate flavor. While optional, I highly recommend using it. The chocolate zucchini cake won’t taste like coffee. Rather, the espresso powder helps bring out the intense chocolate flavor.
  • Salt: Salt balances the flavor.
  • Oil: Oil adds moisture. You can try replacing *some* of the oil with unsweetened applesauce. I’ve done this with chocolate cakes and muffins and the result is wonderful, but I don’t recommend replacing all of it. Regardless of the zucchini inside, this isn’t health food, it’s dessert. Don’t make it something it’s not! 🙂
  • Sugar: We’ll use a combination of brown sugar and white granulated sugar. Brown sugar not only provides moisture, but flavor as well.
  • Eggs: 4 eggs bind everything together and add moisture. Remember room temperature is important.
  • Sour Cream: You can use sour cream or plain yogurt. Either add moisture.
  • Vanilla Extract: Pure vanilla extract adds flavor.
  • Zucchini: There are a whopping 3 cups of shredded zucchini in this recipe. Testing how much we can get away with… without actually tasting it! Zucchini is pure magic in cakes– nothing but flavorless moisture. Same goes with my zucchini bread, too!
  • Chocolate Chips: For mega chocolate flavor, add chocolate chips to the batter. They’re key to those melty pockets of chocolate in each slice. I use semi-sweet chocolate chips, but mini chocolate chips or even dark chocolate chips would pair wonderfully.

wet ingredients in a glass bowl and dry ingredients in a glass bowl

2 images of shredded zucchini on a white cutting board and chocolate cake batter in a glass bowl with a hand mixer

2 round cake pans filled with chocolate zucchini cake batter before baking

Overview: How to Make Chocolate Zucchini Cake

This chocolate zucchini cake comes together quickly and easily! Simply whisk the dry ingredients in one bowl and beat the wet ingredients together in another bowl. Combine the wet and dry ingredients, then add the chocolate chips. The cake batter will be slightly thick thanks to all of the zucchini! Divide the batter between two 9-inch cake pans or you can make a quarter sheet cake using a 9×13 inch cake pan. See my recipe notes for details.

  • Need cupcakes instead? This recipe yields about 24-30 cupcakes. See recipe note.

spreading chocolate fudge frosting onto layer of chocolate zucchini cake on a serving plate

Chocolate Frosting

We’re topping and filling this chocolate zucchini cake with smooth, silky, and creamy chocolate buttercream. We’re using my favorite chocolate buttercream recipe, but increasing the quantity. We do this for my regular chocolate cake, too. If you would rather top this cake with vanilla frosting, use the vanilla frosting included in my white cake recipe. Regardless of which you choose, you’ll have enough frosting to frost the entire layer cake AND a little leftover for some fun piping on top. Decorate however you’d like! I used Ateco #30 tip for the piping.

overhead image of chocolate zucchini cake with piped frosting decorations with a slice cut out

chocolate zucchini cake on a serving plate

Deep, dark, luxuriously rich, crazy moist, and weirdly loaded with vegetables that you absolutely can’t taste. After one bite you’ll be convinced this is the best way to eat your veggies! You’ll love my zucchini oatmeal chocolate chip cookies, too.

More Chocolate Recipes

Print
clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon
slice of chocolate zucchini cake on a black plate with a fork

Chocolate Zucchini Cake

  • Author: Sally
  • Prep Time: 15 minutes
  • Cook Time: 30 minutes
  • Total Time: 3 hours, 30 minutes
  • Yield: serves 10-12
  • Category: Dessert
  • Method: Baking
  • Cuisine: American

Description

This super rich and moist chocolate zucchini cake is topped with milk chocolate fudge frosting- you won’t even taste the vegetables!


Ingredients

  • 2 cups (250g) all-purpose flour (spoon & leveled)
  • 3/4 cup (62g) unsweetened natural cocoa powder
  • 2 teaspoons baking soda
  • 1/2 teaspoon baking powder
  • 1 teaspoon espresso powder (optional)
  • 1/2 teaspoon salt
  • 1 cup (240ml) canola or vegetable oil
  • 1 cup (200g) granulated sugar
  • 3/4 cup (150g) packed light or dark brown sugar
  • 4 large eggs, at room temperature
  • 1/3 cup (80g) sour cream or plain yogurt, at room temperature
  • 2 teaspoons pure vanilla extract
  • 3 cups shredded zucchini (about 3 medium)*
  • 1 cup (180g) semi-sweet chocolate chips
  • chocolate frosting or vanilla frosting

Instructions

  1. Preheat oven to 350°F (177°C). Grease two 9×2 inch cake pans. (Make sure they’re at least 2 inches high, deep dish style.) Set aside.
  2. Make the cake: Whisk the flour, cocoa powder, baking soda, baking powder, espresso powder (if using), and salt together in a large bowl. In another large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the oil, granulated sugar, brown sugar, eggs, sour cream, vanilla, and zucchini together until combined. Pour into dry ingredients and beat on medium speed until completely combined. Beat in the chocolate chips. Batter will be slightly thick.
  3. Pour batter evenly into cake pans. Bake for around 25-32 minutes or until the cakes are baked through. To test for doneness, insert a toothpick into the center of the cake. If it comes out clean, it is done. Allow cakes to cool completely in the pans set on a wire rack. The cakes must be completely cool before frosting and assembling.
  4. Assemble and frost: First, using a large serrated knife, slice a thin layer off the tops of the cakes to create a flat surface. Discard (or crumble over ice cream!). Place 1 cake layer on your cake stand or serving plate. Evenly cover the top with frosting. Top with 2nd layer and spread the remaining frosting all over the top and sides. Pipe any leftover frosting on top. (I used Ateco #30 tip.) Decorate with chocolate sprinkles or mini chocolate chips if desired. Slice and serve.
  5. Cover any leftover cake and store at room temperature for 2-3 days or in the refrigerator for up to 5 days.

Notes

  1. Make Ahead Instructions: Prepare cakes and frosting 1 day in advance. Keep cakes at room temperature, covered tightly. Refrigerate prepared frosting in an airtight container, then bring to room temperature when ready to use. Frosted or unfrosted cakes may be frozen up to 2 months, thaw overnight in the refrigerator and bring to room temperature, if desired, before serving.
  2. Special Tools (affiliate links): Box Grater, Glass Mixing Bowls, KitchenAid Stand Mixer, KitchenAid Hand Mixer, Round Cake Pan, Cupcake Liners, Cupcake Pan, #30 Ateco Closed Star Tip, and Disposable Icing Bags
  3. Blot the Zucchini: Give the shredded zucchini a very light blotting with a towel. Don’t squeeze too much moisture out, just a little blot before adding to the wet ingredients. I own and love this box grater— works quickly!
  4. 9×13 Cake: Interested in making a sheet cake instead? This batter will fit into a 9×13 pan. The bake time is long– at least 45 minutes to ensure the thick cake is baked through. Same oven temperature.
  5. Cupcakes: This recipe yields 24-30 cupcakes. Bake for 18-22 minutes or until a toothpick inserted in the center comes out *mostly* clean with no wet batter. Same oven temperature.

Keywords: chocolate zucchini cake

Also try these as cupcakes! Directions in the recipe notes.

chocolate zucchini cupcake topped with chocolate fudge frosting

254 Comments

  1. janey dailey says:

    Hi Sally!  I have a question I hope you can answer.  I have several one cup bags of pureed zucchini in my freezer and would like to make your Greek yogurt zucchini bread.  Your recipe calls for shredded zucchini and I’m wondering if I can substitute my pureed zucchini?  I’m thinking the moisture may be an issue.

    1. Hi Janey– that would be way too much moisture for the bread. Shredded it best. Thank you!

  2. Simy Mathews says:

    Sally I made this yesterday and it is the most decadent cake I have made so far! Absolutely fabulous. So soft that I could turn a huge piece in a ball and pop it into my mouth. Lush!! I used a frosting made of dark and white chocolate and some creamy peanut butter and that took this cake to another level. Thanks for this recipe!

  3. Made this yesterday as a 9×13 cake with your chocolate frosting you suggested. Phenomenal! I had to use avocado oil because I was out of canola and mini chips for the chocolate chips. This is an insanely good recipe, even using the avocado oil which probably alters the taste slightly. And the chocolate frosting is amazing. I always make your vanilla one so I can’t believe I’ve never tried this one. Thanks for a great recipe.

  4. People, you need to bake this cake. YOU NEED TO BAKE THIS CAKE!! I brought it to a dinner last night and at first just called it a chocolate cake. I received glowing reviews like “This is the best chocolate cake I’ve ever had”, “You should enter it at the state fair”, “What a unique chocolate cake!” One lady told me literally four times how good it was. And then I dropped the bombshell that it had zucchini in it. People were just blown away at how rich and yummy it was. Sally, you outdid yourself on this one! By the way, I made the milk chocolate frosting with half butter and half shortening, and it was just right.

  5. I made it with a chocolate cream cheese icing instead but used the cake recipe exactly as written for a 9 x 13 pan since my layer cake skills are non-existent. The cake was amazing! Loved the chocolate chips for a little surprise. So glad you included the option for a 9 x 13 pan because I would have missed trying this otherwise. Thanks!

  6. Great recipe. Made it for a friend’s birthday this weekend and was really pleased with it. Probably one of the most chocolately chocolate cakes I have made.

  7. I made this the other day for my husband’s birthday. He requested a chocolate cake with chocolate frosting and I thought this would be perfect. The zucchini definitely makes us feel less guilty about eating it. 🙂 The cake is moist and beyond delicious! Thanks for yet another great recipe!

  8. Sierra Fennell says:

    Hi Sally!
    My, what a delicious cake recipe!! I did change the pan it baked in and instead baked it in a bundt pan while increasing the time by almost triple at 350 in the oven. It came out amazing and talk about ooey gooey! I would related this cake more so to a brownie’s sibling because of how moist and tight crumbed it is. Thank you so much!!

  9. Good god this is a good cake. It is probably the moistest chocolate cake I’ve ever tasted. The only thing I found is a lot of the chocolate chips sunk to the bottom of the pan, and when the cakes were turned out, they stuck in the pan. I used your chocolate fudge frosting recipe, delicious. Now I can’t stop eating it!

  10. Can you use instant coffee powder instead of espresso powder like in the double chocolate zucchini bread? It called for 2x as much instant coffee powder as espresso powder in the bread, and I was curious if it would be the same ratio in the cake??
    PS: I have made 4 batches of double chocolate zucchini bread and 4 batches of your award winning zucchini bread, and we can’t stay out of them! I had to stick half of the loaves in the freezer to keep us from eating them

    1. Sure can! I’d use 1 and 1/2 teaspoons (or up to 2 tsp) instant coffee in this cake.

  11. Sally, I made this cake and oh my gosh it is amazing. I froze part of it with icing on it and it did great. I took it to my Sissy and first bite her eyes rolled back in her head. Her son is getting married next year and she told me THIS IS IT! We are on the search for cakes to make for the rehearsal dinner and she wants me to make them for her. She said This is the one for the Grooms Cake! If her son falls for it the way she did. But she has to stay out of the rest of it for him to try it. haha. I have a feeling I will be making at least one or two more of your cakes for the rest of the dinner but we are still in the deciding fase. You have made me such a Hero! I have found the extra ingredient in everything is The Love! Or least she says so. Oh i made your double choc zucchini bread and regular zucchini bread in one day (double batches) also. Oh my goodness they are so amazing. She says the double choc. is Nervana! They freeze well so that makes it even better. Thanks! I didnt use coffee in mine as we hate coffee and it was still great.

  12. I am now making another batch. Second one in 2 weeks. Really great cake! Everyone I have a piece to loved it!  

  13. I just baked this cake for my 25th Wedding Anniversary, tomorrow. Is it absolutely necessary to let the layers cool completely in the pans? This is a first for me. Thanks!

    1. Yep, otherwise they may stick.

  14. We have an overload of zucchini in our garden this year and it just so happened to be my dad’s birthday yesterday. He’s a huge chocolate fan so it only seemed right to make a chocolate zucchini cake with chocolate icing. And boy! Are we ever glad we chose your recipe! It was a huge success in our family and everyone went crazy for the moist chocolate cake… Let’s just say there is no more cake left today. Next up, we’re going to try your double chocolate zucchini bread.
    Thanks for the wonderful recipe! It’s a keeper for sure 🙂

  15. Can i subtitute natural cocoa with dutch cocoa and remove the baking soda and replace them with twice amount baking powder? 

    1. I don’t suggest it.

  16. Hi! I want to bake a chocolate cake this weekend, but can’t decide between this chocolate zucchini recipe or your triple chocolate layer cake recipe. Could you tell me how the results of each one will differ in terms of taste/texture etc? Thanks!

    1. They are both rich and moist and you can’t go wrong either way!! The chocolate zucchini cake has chocolate chips inside the batter so if you want more texture try this one.

  17. Hi….I want to make the Chocolate Zucchini Cake & I want to use espresso powder…. I have looked in the grocery stores in the coffee area but I don’t see it.
    What kind of a container does it come in?

    Also you suggest chocolate fudge frosting or vanilla frosting…so I clicked on it and it brought me to a page that had Milk chocolate frosting….where do I find the chocolate fudge frosting recipe?

    Please reply. Thanks.

    1. Hi Patricia, The espresso powder usually comes in a can or jar and in my local stores is on the shelf next to the instant coffees. The chocolate fudge frosting IS the milk chocolate frosting – they are one in the same! 🙂

  18. So this cake is amazing! All I had was Hershey’s dark cocoa powder so I used that in the cake and frosting and it was amazing. So moist and rich. Thank you for the recipe! This is the exact kind of texture and moistness I want in my chocolate cake and sometimes a homemade chocolate cake doesn’t always result in it… at least for me. But this one does not disappoint!

  19. Yasmine Maggs says:

    Hey Sally. Made your Chocolate Courgette Cake yesterday and it was amazing! Probably the best chocolate cake I’ve ever tasted. Thank you so much. I love your recipes & website. Lots of love from the UK. x

  20. I’ve tried a lot of zucchini chocolate cakes over the years, but this one is my favourite by far…just awesome! I made it in a 9×13 pan, and the only change I made was to use 1/2 cup milk choc chips and 1/2 cup semi.

  21. Just made this cake with the chocolate frosting. I made it exactly as shown but did not add the espresso. It is absolutely amazing and super moist.

  22. Austria Azaceta says:

    Hi Sally!
    So I made this cake last week (frosting & all) for my sister’s birthday & just had to let you know how incredible it was.  So so so so so goooooood!!!  The espresso powder is EVERYTHING!  It was super moist fluffy cake & such amazing chocolate flavor without being super sweet.  I even got yelled at by my brother in law for (& I quote) “making such delicious cake”. 🙂
    Thank You!!

  23. Hello Sally! I love your site and got your baking addiction book for my birthday and cannot get enough!! I am going to try this recipe for a birthday, and I was wondering what is the frosting you used on this cake ? I saw you had a link to the chocolate fudge frosting but when I clicked it brought me to the Milk chocolate frosting …. is that the same ? Thanks a lot !!

  24. Mari Eriksson says:

    Dear Sally, Your blog is amazing. I love your photography and your recipe are all wonderful. I did your Chocolate zucchini cake for a dinner party and it was a super hit with everybody. It is a very nice feeling when people tell you things like this reminds me of my mother when she decorated cakes when I was little. Thanks for your very informative text and gorgeous recipe. All the best from Sweden

  25. Just made this cake over the weekend and it was gorgeous. I would like to experiment with different frostings as the sponge is perfect so I would like variations. It is the perfect recipe whether you make it as bread, muffins, cupcakes or cake so it’s now a favourite of mine and my husbands. Thanks Sally! 

  26. Hello Sally. I want to thank you for this absolutely amazing cake. My family has found what decadent really means. This was a big time hit at our Christmas Eve gathering with so many wonderful comments. And there is still more left for us to eat today. Yeah.

  27. Hi Sally,

    I am planning to make this cake for my birthday’s son. I purchased the cake pans clicking on the link above but I got 8 X 2 (2) pans. Now I am confused because the recipe asks for 2 pans 9 X 2. Can I use the one I got or I would need the 9 X 2 pans?

    1. Hi Pola! You can use 8-inch pans instead. The bake time will be slightly longer.

  28. I have a terribly difficult question for you… How is it that I am supposed to get this batter into a cake pan before I EAT IT ALL!!!! Oh my gosh… I need help!!. my only switch was to use coconut oil rather than vegetable oil… it is one of my favourite things to use for chocolate cake. Now my further quandary is whether to go with the Chocolate buttercream, Chocolate ganache, or your Peanut butter icing recipe! Decisions!

  29. Made your chocolate zucchini cake yesterday for a friend’s birthday and frosted it with Hersheys dark chocolate frosting because that what I had ingredients on hand to make. I saw the comment above about using ganache and I would like to try that as well, or peanut butter frosting and ganache… what the heck! I used a 13×9 inch pan and it took fully 60 mins. to bake. So thick and dense and moist and chocolatey!!! YUMMO! Thank you so much and I WILL be making this again and again!

    1. I’m glad you enjoyed it, Debbie! It would be outrageous with peanut butter frosting and ganache!

  30. Sally, Sally, Sally! I have yet to bake ANYTHING from your website that wasn’t delicious. This chocolate zucchini cake is no exception. It is extremely moist and if I hadn’t baked it myself, I’d have never know it contained zucchini. I opted for a 9×12 single layer cake and it turned out perfect. Thanks for being my go-to website for delicious recipes. I love baking and knowing I can count on your recipes to be so scrumptious makes it even more fun! I’m on to your cherry pie next… love those summer fruits and veggies!

1 2 3 7

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe rating

This site uses Akismet to reduce spam. Learn how your comment data is processed.

With kitchen-tested quality recipes and step-by-step tutorials, my goal is to give you the confidence to bake and cook from scratch.

Sally's signature

Recipes You’ll Love

Archives

Categories

Join the community on the 1st of every month as we tackle a new challenge recipe. Review Sally's Baking Challenge FAQ page if you have any questions.

View More

A tradition since 2013, every December we countdown to Christmas with 10 new cookie recipes in a row!

View More

The first week of every November is all about Thanksgiving Pies.

View More

My Cookbooks

Sally's Cookbooks

About Sally

Welcome to my Kitchen!

I’m Sally, a cookbook author, photographer, and blogger. My goal is to give you the confidence and knowledge to cook and bake from scratch while providing quality recipes and plenty of pictures. Grab a cookie, take a seat, and have fun exploring! more about Sally

×