Super moist and indulgent chocolate zucchini cake is studded with chocolate chips and topped with chocolate fudge frosting. Made with 3 cups of shredded zucchini (you can’t taste it!), this is the most decadent way to eat your greens.
I originally published this recipe in 2017 and have since added new photos, a video tutorial, and additional success tips.
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! Zucchini recipes have never been more decadent than this one. 🙂
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 is the hidden vegetable inside. If you’re one who believes these veggies should only be in zucchini casserole, zucchini fritters, or zucchini biscuits and have nothing to do with dessert, keep an open mind. Carrot cake, anyone?!
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
- A delicious way to use up a bumper crop of summer zucchini
- 3 cups of vegetables hiding inside—and you don’t even taste it
- Covered in fudge-like chocolate buttercream
One reader, Stacie, commented: “Delicious chocolate cake! No evidence of three cups of zucchini in there! So good!!! ★★★★★“
One reader, Emily, commented: “This was amazing! Probably the best chocolate cake we’ve ever had—so moist! And no one even guessed there was zucchini in it. ★★★★★“
One reader, Kara, commented: “This wasn’t just the best zucchini recipe I’ve ever tried, it was the best cake recipe as well! The zucchini here makes this moist and fudgy, almost like a brownie, but still fluffy like cake. I used cream cheese frosting and it was divine. I will be making this for birthdays in the future! ★★★★★“
Overview: Chocolate Zucchini Cake Ingredients
This decadent cake is made with fresh 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 a few key ingredients:
- 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.
- 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. We use it in chocolate zucchini bread and in this chocolate cake roll, too. You can find espresso powder in the coffee aisle at the grocery store or online.
- 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. Despite the zucchini inside, this isn’t health food, it’s dessert. Don’t try to make it into something it’s not!
- Eggs: 4 eggs bind everything together and add moisture. Remember that room-temperature ingredients are important.
- Sour Cream: Just like in chocolate peanut butter cake, you can use sour cream or plain yogurt. Either add moisture.
- Zucchini: Use 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, apple zucchini bread, and zucchini muffins, too!
Optional 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 (just like in my peanut butter chocolate chip zucchini bread), but mini chocolate chips or even dark chocolate chips pair wonderfully, too.
Let Me Show You How to Make It:
This chocolate zucchini cake comes together quickly and easily, just like my regular zucchini cake. 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 the recipe Notes section for details.
- Need cupcakes instead? This recipe yields about 24–30 cupcakes. See recipe Notes.
Chocolate Frosting
We’re topping and filling this chocolate zucchini cake with smooth, silky, and creamy chocolate buttercream. You’ll use my favorite chocolate buttercream recipe, but increase the quantity as directed in the recipe card below.
How to Assemble a Layer Cake
If you’re new to assembling and layering cakes, or if you just need a refresher, see my How to Assemble a Layer Cake video tutorial. The quick video guide will walk you through how to stack and decorate it.
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 Wilton 1M for the pictured piping:
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
- Chocolate Lava Cakes
- Flourless Chocolate Cake
- Chocolate Cake
- Chocolate Cupcakes
- Homemade Brownies
- Inside Out Chocolate Chip Cookies & Double Chocolate Chip Cookies
Chocolate Zucchini Cake
- 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 the best chocolate frosting—you won’t even taste the vegetables!
Ingredients
Cake
- 2 cups (250g) all-purpose flour (spooned & 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 (about 360g) shredded zucchini (lightly blotted; see recipe Note) (2 medium zucchini, about .75–1 lb.)
- 1 cup (180g) semi-sweet chocolate chips (regular or mini)
Chocolate Buttercream
- 1 and 1/4 cups (282g) unsalted butter, softened to room temperature
- 3 and 1/2 cups (420g) confectioners’ sugar
- 3/4 cup (62g) unsweetened cocoa powder (natural or Dutch-process)
- 3–5 Tablespoons (45–75ml) heavy cream (or half-and-half or whole milk), at room temperature
- 1/4 teaspoon salt
- 1 teaspoon pure vanilla extract
- optional for decoration: chocolate chips and/or chocolate sprinkles
Instructions
- Preheat oven to 350°F (177°C). Grease two 9-inch round cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (If it’s helpful, see this parchment paper rounds for cakes video & post.)
- 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 attachment, beat the oil, granulated sugar, brown sugar, eggs, sour cream, and vanilla together until combined. Add the zucchini and mix to incorporate. Add the dry ingredients to the batter and beat on medium speed until completely combined. Fold in the chocolate chips. Batter will be slightly thick.
- Pour batter evenly into cake pans. Bake for around 28–32 minutes or until the cakes are baked through. To test for doneness, lightly poke the top of the cake with your finger—if it bounces back instead of leaving , the cake is done. Or you can insert a toothpick into the center of the cake—if it comes out clean, it’s done.
- Set the cakes on a cooling rack and let cool in the pans for 1 hour. After 1 hour, remove the cakes from the pans, discard the parchment rounds, and let the cakes finish cooling directly on the rack. The cakes must be completely cool before frosting and assembling.
- Make the buttercream: With a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed until creamy, about 2 minutes. Add confectioners’ sugar, cocoa powder, 3 Tablespoons of cream, salt, and vanilla. Beat on low speed for 30 seconds, then gradually increase to high speed and beat until it’s smooth and creamy. Do not over-whip. Add 1/4 cup more confectioners’ sugar or cocoa powder if frosting is too thin or 1–2 more Tablespoons of cream if frosting is too thick. (I usually add 1 more.) Taste. Add another pinch of salt if desired.
- 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, cake turntable, or serving plate. Evenly cover the top with a heaping cup of frosting. Top with 2nd cake layer and spread the remaining frosting all over the top and sides. Pipe any leftover frosting on top. (I used Wilton 1M tip.) Decorate with chocolate sprinkles or chocolate chips if desired. Slice and serve.
- Cover leftover cake and store at room temperature for up to 2 days or in the refrigerator for up to 5 days.
Notes
- 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.
- Special Tools (affiliate links): Box Grater | Glass Mixing Bowls | Electric Mixer (Handheld or Stand) | 9-inch Round Cake Pan | Cake Turntable | Wilton 1M Piping Tip | Piping Bag (Reusable or Disposable) | Cake Carrier (for storage)
- 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!
- 9×13-inch Cake: Interested in making a sheet cake instead? This batter will fit into a 9×13-inch pan. The bake time is long—at least 45 minutes to ensure the thick cake is baked through. Same oven temperature.
- Non-Chocolate Zucchini Cake: Looking for zucchini cake without chocolate? Here is my regular zucchini cake topped with brown butter cream cheese frosting.
- 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.
Instead of cake, try these as cupcakes! Directions in the recipe Notes above.
Reader Comments and Reviews
Can this be baked in a Bundt pan?
Absolutely the BEST!!!!
This is an excellent recipe! ❤️❤️❤️ I read that mixing the zucchini with the dry ingredients before adding the wet ingredients keeps them from clumping, as well as the chocolate chips (I also like using minichocolate chips and really like the way they mix in). I do this each time and don’t have trouble with anything sinking to the bottom. Thank you again for a great recipe!
Making this tomorrow. Sounds fantastic. Using 9×13 sheet pan. Do I need to use parchment paper? Love your recipes. Haven’t had a bad one yet. Thank you.
Hi Linda! No need to use parchment in a 9×13 pan if you plan on serving the cake from the pan. Thank you so much for making our recipes!
Hi Sally! This is my favorite chocolate cake recipe that helps me use up my summer squash over abundance each summer! Any tips on how I could add a Guinness stout beer to this recipe? I know I need to keep the moisture level the same…do you have any recommendations on how I could adjust this amazing recipe to incorporate the Guinness flavor? Thanks!
Hi Anna! Without altering the cake recipe, you could frost the cake with the Guinness chocolate frosting from our Guinness cake recipe. Let us know if you try!
Delicious. Super moist. Frosting is also very good. I made 3 eight inch layers with caramel and ganache in between. Frosted it with your frosting, which piped beautifully. Would post a pic but it won’t let me.
Question: my cake isn’t raising, is it supposed to raise?
Hi Mary! Yes, the cake should rise in the oven. Could your baking soda or baking powder be old? Did you use natural cocoa powder (not Dutch process)?
Very good! Perfectly chocolatey and moist. Kept well for months in the freezer.
Well I don’t know what u all are talking about this cake had no chocolate taste at all. More like cardboard. Even the icing was bland.
Made this with part of a baseball bat-sized zucchini my neighbor gave me, and it turned out great! Moist and with a deep rich chocolate flavor, like the ones I remember making several years ago. I used Ghirardelli dark chocolate chips, which didn’t add too much sweetness, but it would have been just as good without them. I elected not to frost since I really didn’t think it needed it & it was just for us.
This is a wonderful velvety cake, even our grandkids love it.
I have made this cake several times always moist and delicious,and everyone loves it. Thank you for this recipe.
I made this exactly as written and it was so delicious! Moist cake with nice chocolate flavor and the frosting was light and fluffy and perfect. I will definitely make again!
I have zucchini now, birthday in weeks. Can I freeze, either frosted now or later?
You bet! See Notes after this recipe for details. Happy baking 🙂
Love this cake. The chocolate chips sunk to the bottom of the cake. Should I have dusted them with flour? Maybe that’s what suppose to happen? Excellent cake
Hi Bonnie, you can definitely toss your chocolate chips in a bit of flour before adding to the batter next time, and that should help with any sinking. We’re so glad you enjoyed the cake!
Great recipe but if you’re baking in a 9×13 glass pan, I’d definitely recommend turning the temp down to 325 and start checking for doneness after 40 minutes. I followed recipe instructions and 350 for 40 minutes was overdone.
This is the best chocolate cake I’ve ever made. Thank you for sharing this recipe. Next time I will skip the frosting. So good.
Do you think I could make this in a Bundt cake pan?
Hi Jill, certainly! We’re unsure of the exact bake time for a Bundt cake, but it will take well over the time needed for the cake layers. Keep a close eye on it and use a toothpick to test for doneness. Hope it’s a hit!
Jill, I’d love to hear if you tried it in a bundt, and how it came out. How long did you bake it?
My batter was super runny???
Hi SY, the batter should be slightly thick. Was your zucchini especially wet and did you blot lightly before adding to the batter? If the zucchini seemed especially wet, it could be that it added too much additional liquid to the batter. How did you measure your flour? Be sure to spoon and level (or use a kitchen scale) to ensure the flour isn’t under-measured, which could cause the batter to be too thin.
I’ve been making this recipe for years, and it is hands down the best chocolate zucchini cake I’ve ever had. My brother runs a small organic farm and he always loads me up with excess squash every summer. I do 2 loaf cakes without the frosting (my husband has high cholesterol), but swap the espresso powder with orange zest and then top them with a simple powdered sugar glaze using the juice from the orange. It is divine!
For those asking if it works with other summer squashes, the answer is yes! Try it with pattypan, you won’t be disappointed.
Simply Devine
I’m not a chocolate cake fan, and I had a zucchini choc cake recipe years ago that I have misplaced. Tested another recipe before I found this one and it is so delicious, super moist and easy to make. Everyone that tasted it has asked for the recipe. I made mine in one large tin and a few muffins to test how it bakes and no need add frosting/butter cream this cake is perfect just as is.
I just made the simplest version, using a 9×13 pan and with no icing or expresso powder. It was ready in a little under 45 minutes, and it was delicious!
Do you mean
“ 2 teaspoons baking powder
1/2 teaspoon baking soda”?
I made it as written. It’s definitely delicious, but it tastes slightly off. Thanks!
Hi Lynn, yes, it’s correct as written. I’m sorry it tasted off. Did you alter any other ingredients? We want to make sure the batter is balanced with enough acid to react with the baking soda.
If I only have cake flour and white sugar, will those substitutes still work?
Hi Milynn, cake flour is too light for this cake. We recommend waiting until you have the correct ingredients to make it for best results.
I made this with gluten free flour! I let the batter sit for 20 minutes before I put it in the oven. Gluten Free flour often needs a bit more time to absorb liquids. I also added some of the espresso powder to the frosting. The cake turned out extremely moist and very delicious. The family loved it.
Could I bake this in a Bundt pan? I know cooking time will be much longer.
Hi Nancy, certainly! We’re unsure of the exact bake time for a Bundt cake, but it will take well over the time needed for the cake layers. Keep a close eye on it and use a toothpick to test for doneness. Hope it’s a hit!
Hi sally
Eggless version pls
Whst is substitute
Hi Anita, we haven’t tested an egg-free version of this cake. If you’re interested, here are all of our egg-free recipes.
My husband does not like zucchini but he loves this chocolate zucchini cake. A great way to enjoy our garden’s abundance.
I was 1/2 cup short of cocoa when I got to the frosting so I melted baking chocolate (2oz 100% cocoa and 2oz of 60% cocoa) and mixed it in with the 75ml of heavy cream and added it to the frosting mix. Delicious!
Will this cake bake up well in a Bundt pan?
Hi Mandy, We’re unsure of the exact bake time for a Bundt cake, but it will take well over the time needed for the cake layers. Keep a close eye on it and use a toothpick to test for doneness. Hope it’s a hit!
I made this with the German chocolate topping from the Upgraded German Chocolate Cake recipe and it was perfect!
Tried your choc Zuchinni cake tonight. Happy , so far!
But where I’ve really learn3 from you respectfully, too, is your pie pastry and your fruit pie guidelines. Esp tips for peaches pies! My friends say it’s the best peach pie ever and I always share your guidance and tips and happily give you credit you deserve!
* between paragraphs I pulled the cakes in two pans out and will frost in the morning. They look terrific! One with chopped CA walnuts and one without —for the younger grandkids! Thank you!
would you please share the peach pie guidlines and recipe for pastry
Here’s our peach pie recipe and our pie dough recipe, Darlene!
I made this in a 9×13. Done after 45 minutes. I made a simple chocolate ganache topping.. amazing!! I love all of your recipes. Can’t wait to get the cookbook!