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.

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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 (63g) 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

444 Comments

  1. Something else I can make with the boatload of zucchini we have now sitting in the kitchen! Thanks, appreciate the idea. I also love double chocolate zucchini muffins.

  2. That looks so decadent that it’s hard to believe there is zucchini in it!
    Kari
    http://sweetteasweetie.com/beeritas-estrella-jalisco/

  3. I make a delicious, chocolate zucchini quick bread. This cake looks phenomenal, can’t wait to try it out!

  4. It’s funny how my first two thoughts were: “I am SO not telling my kids there’s zucchini in here.. muahaha” and “I’m just gonna keep telling myself there’s zucchini in here… then I can eat as much as I want, right!?” LOL. No matter what I tell who, this looks absolutely divine.

    1. HAHA! Thanks Karly 🙂

  5. This is beautiful Sally, thanks so much. Can’t wait to make this cake. We have tons of fresh raspberries in the garden, and I think I’ll serve this cake with a little whipped cream and a ton of raspberries. I made your oatmeal raisin cookies for the 334th time this weekend. Usually I am very open for kitchen experiments, I tried Ambitious Kitchen’s black bean avocado brownies and can’t say I care much for the earthy aftertaste. A great veg to add however is chickpeas, or at least in my experience! Chocolate-covered Katie has a chickpea chocolate chip cookie recipe, you should give it a look! Have a lovely week. 

    1. Good to know about chickpeas!! And you can’t beat a batch of homemade oatmeal raisin cookies. 🙂 Let me know when you try this cake, I’d love to hear how it is with the whipped cream and raspberries!

      1. Sally, I made it yesterday for our Sunday afternoon coffee hour. I reduced the sugar to half a cup of brown sugar and 2/3 cups of granulated sugar, because we Frenchies like it less sweet 🙂 I also subbed half the oil for applesauce. Topped it with your ganache from the Party Angel Food Cake, tons of fresh raspberries and a generous dollop of whipped cream from our neighbour’s cows. It was a huge success with everyone! Thank you so much! Next week, I will be making your peach Bundt cake. Can’t wait!

      2. I bet it was DIVINE with the chocolate ganache!!

  6. 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!

    1. I’m so glad you tried it already! Thank you for reporting back already 🙂

    2. Do you mind if I ask what frosting you used for this?! Sounds amazing and I’m making this cake over the weekend! 

  7. This looks delish! Definitely want to try!!

  8. Shawnna Griffin says:

    hey girl- this cake looks so yummy!

  9. 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.

    1. You are welcome! I’m so glad the oil swap worked for you!

  10. This looks beyond heavenly!!!

    Also, I love the link to the cocoa powder baking basics post! Super helpful in understanding how the two are different.

    1. I’m glad you find that helpful!

  11. We moved into our house two years ago and decided this year to clean up the former owners’ garden and plant our own. Our zucchini is going crazy, so I am super excited to make this.   As mentioned when you first spoke of this cake, I dream about your chocolate zucchini bread, so I am getting on this over the weekend!! 

    I hope you’re feeling well. I was VERY pregnant with my oldest during the Summer.  I spent many days soaking my swollen ankles in cool water!  

    1. I’ve been dipping my feet into the kiddie pool I bought my dogs most afternoons HAHA! So I get it!

    2. My daughters & I baked this cake today and frosted it with the chocolate fudge frosting. The cake stuck to my pans (I think it was the chocolate chips), but once I assembled & frosted it, I didn’t mind! It didn’t look the prettiest, but we didn’t care. This cake is wonderful!  My chocoholic husband had no idea there was zucchini in it…and I’m keeping it our little secret.  Make this cake-you will love it!
      Thanks for another great recipe, Sally.

  12. YES GREENS IN CAKE! love love love! And UGH…. no black bean brownies for me… I’d rather have this any and every day! 

  13. Kelli @ Hungry Hobby says:

    YUMMMY you can’t even see the zucchini! sometimes my hubby finds a piece of veggie in a baked good of mine and immediately rejects it ha ha

  14. Cindy @ The Sweet Nerd says:

    Best line ever: “…this isn’t health food. It’s dessert! Don’t make it something it’s not!” I’m constantly trying to sneak in veggies but honestly at the end of the day – it IS the sugar and chocolate and more chocolate that we want to taste. 

    1. Hahaha exactly

  15. LLYARBOROUGH says:

    Looks yummy. If only my zucchini were ready. Delayed gratification is better than none. I’ll bookmark it. 

  16. Sally, I watched you make this as cupcakes on Instagram live the other day. Are you following a pregnancy diet/workout routine? I’d love to know. You look amazing!

    1. Thank you! I’m just trying to stay as active as possible and eat as nutritious as I can for the baby. 🙂

  17. Kelly Senyei @ Just a Taste says:

    This cake looks so delicious, Sally! And I love all that hidden zucchini! 

  18. hello Sally from the philippines!! made this and it was the moistest and most delicious chocolate cake to date 🙂 though i don’t have enough zucchini since its a bit pricey here in PH but i increase the sour cream to a cup..this is my first time to comment here but had made some of your recipes already and always turn out great 🙂 thank you soo much and congratulation on your pregnancy been working on my 2nd but hasnt formed yet huh:( well in Gods perfect time it will 🙂 by the way wanted to ask if what to replace opting not to use the zucchini, planning to make cupcakes ? thank you and goodluck 🙂

    1. Best of luck to you!
      And, also, about the cupcakes: I would just make these chocolate cupcakes instead of messing around with this chocolate zucchini cake and leaving out the zucchini.
      Thanks for taking the time to say hi!

  19. Since the cakes can be frozen frosted I’m guessing the cupcakes can also be frozen the same way?  Love freezing cupcakes so that I can take them out for the kids as a special treat whenever needed!  Same with so many of your other desserts!  I also find it keeps me from overindulging by having too many desserts out on the counter at once

    1. Hi Taylor! Yep, the frosted cupcakes freeze well too. Obviously taste better fresh, but will still be great!

  20. Dear Sally, I will be forever grateful to you for this recipe. I’m 67 and never baked with zucchini! 🙂 You made this recipe sound sooo delicious I just had to try it! WE LOVE IT!!! I think it was July 10th when you posted; my dear hubby needed some cupcakes for a morning meeting and I made this recipe! Yesterday I made them, the second time, for a niece who was packing for camping, was so busy, and appreciated the offer to take these along. (I saved a few for us!) It is so very moist and full of chocolate flavor. Sometimes my husband and I say, “If we had our eyes shut, we wouldn’t know this cake is chocolate!” Not this cake. So grateful you shared this with all of us! Thank You! (And, God’s blessings on your last 10 weeks as you wait for precious Baby to arrive.)

    1. Thanks for the well wishes during this exciting time for us, Cordelia!

      Also, thank you for writing to tell me how much this chocolate zucchini cake was loved! It’s absolutely my new favorite way to make chocolate cake because it’s so rich and divine, but there’s hidden veggies 🙂

  21. People, you need to bake this cake. YOU NEED TO BAKE THIS CALE!! 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.

    1. HAHAHA!!! I love this comment it made me laugh. I brought these cupcakes to our friends the other night and received the same absolute SHOCK that there’s zucchini inside!

  22. I can’t wait to make this recipe, it looks delectable!!! Where can I find the sprinkle cake plate?

    1. My sister-in-law painted it for a wedding gift– so it’s custom made!

  23. 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!

    1. Thanks so much for reporting back, Scott! Happy it was a big hit.

  24. 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.

  25. 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!

    1. You are welcome, Erin! And yes, the veggies are not only for moisture but also to reduce the guilt 😉

  26. 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!!

    1. Love that you turned it into a bundt! 🙂 Thanks so much for reporting back.

  27. Yes, I made this. Great cake but cut back the sugar to 3/4 cup white and 3/4 c coconut sugar. I used 1 Cup of white flower and 1 Cup of sprouted grain flour. It was still plenty sweet and will cut back the sugar further next time. I also wanted it thinner so divided into two 9X 13 pans. It was perfect. Great chocolate flavor and would never know it contained zucchini.

  28. 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!

    1. Thanks for reporting back, Chris!!

  29. Ashleigh Monaco says:

    I highly recommend trying black bean brownies! Dana at Minimalist Baker has two amazing recipes for black bean brownies — there’s peppermint black bean brownies and turtle black bean brownies (think pecans, coconut, and chocolate)! I have tried both and they are sooooooooo delicious and addicting. 😀

    https://minimalistbaker.com/vegan-peppermint-black-bean-brownies/

    https://minimalistbaker.com/refined-sugar-free-black-bean-brownies/

    1. YUM!! Thanks so much for the recommendations!

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