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
This was a hit when I brought it to work for a birthday. Lots of compliments and “I just can’t stop eating cake” comments. Will definitely make this again! Loved the frosting too.
I made this cake for my sister-in-law’s birthday and I ABSOLUTETLY LOVED IT! Will be making this again for the weekend.
This cake recipe is excellent. I made it in a 9 x 13” pan at 350 and baked for 50 minutes. I baked it on parchment paper, and while it was heavy, I was easily able to remove it to place on a tray. I used a mix of Hershey’s and Wincrest unsweetened black cocoa and frosted with homemade cream cheese frosting. I took it to a party and it was inhaled. Your measurements and instructions were spot on and I appreciate you going to the trouble to share this delicious dessert with us!
My family was silent while eating this dessert! Absolutely delicious and easy!
If you just have the standard 9×1.5″ cake pans (not deep dish style), would you recommend dividing the batter into 3 cakes or would they be too thin this way?
Or i have deep dish square pans (8×8), would 2 of these work and just do a square cake instead of a round one?
Alternatively I could just fill the current cake pans up to a certain level (what level do you recommend, 3/4?) and the rest make a few cupcakes? Preferably do an entire cake with layers (not interesting in doing a 9×13).
Hi Cora, I think making it into a three layer cake would be just fine! Each layer will be thinner so just keep in mind that your bake time will likely be shorter. Hope you love it!
This was the most delicious chocolate cake! I brought this to a weekend gathering of friends. They went crazy for it, they just couldn’t believe there was zucchini in it.
I did, however, use a different recipe for the icing. It was a recipe that was a little more difficult to make than yours but was incredibly delicious with this cake. It is also a milk chocolate icing but was a custard based icing but friends said it was delicious and not too sweet.
This cake is incredible!
I’m making this for our church luncheon tomorrow to celebrate all 3 of my kid’s birthdays. My middle daughter’s birthday was July 15, my youngest daughter’s birthday is Monday and she will be 5, and my oldest child my son his birthday is Tuesday and he will turn 14.
Wow! This recipe is amazing! Made as cupcakes and they were so chocolaty yet still light and fluffy! Thank you for this delicious recipe. I have it pinned and will absolutely be making it again!
You can never have too much zucchini if you bake this cake all summer! Super moist! Chocolate! We loved it! Thanks Sally!
I made this in a 13×9 pan. It was DELICIOUS!! It was moist and it was hard to believe there was zucchini in it
This is now my “go to” chocolate cake. The grandsons love it and so does my husband. Neighbors, too! I’ve brought it to dinner parties and served it to my classmates as unadorned mini-cupcakes. Everyone agrees with you, Sally, this is a super recipe.
This cake is a legend in our family. Just had a request for it yesterday from my sister-in-law.
Made this into cupcakes for a family gathering and everyone LOVED them. Thank you, Sally, for doing all of the work and making me look so good.
Hi Sally,
Let me just say that I have made this amazing cake and with cup for cup gluten free flour and it was out of this world and YES!!! you would never know that there is a vegetable in this luscious cake! Love your recipes, they are always a hit!
Rosetta
Flippin yum! Terribly moist. Could maybe use more sugar, but even zucchini haters love it! Was looking for ways to use up my too many zucchinis from garden. This recipe was the jackpot!♥️
Made these as cupcakes and they are soooo good!! So chocolatey and delicious and so moist!! This recipe is a keeper for sure!! Thank you Sally!! I love your recipes and this joins my ever growing list
Can the oil be replaced by butter?
I don’t recommend it for this cake recipe.
Can I use a bundt cake pan?
Hi Cindy! I haven’t tried this as a Bundt cake but readers have had success 🙂 Bake at 350 Fahrenheit for almost triple the time. Keep an eye on it!
Can you use a gluten free flour?
Hi Sarah! I don’t have any experience baking with gluten free flour but other readers have reported back that they use it successfully in my recipes. Let me know if you try it!
Hi Sally. Fantastic and super moist layer cake! Made it for the first time last week and already have someone asking me to make it again. He would like some pecans in it though and I assume it would work well…. any idea of how much I could get away with in the batter though? 1 cup total? Less? Thanks!
Hi Marine! I recommend 3/4 cup – 1 cup chopped pecans. Yum!
This cake looks amazing!! I’m curious is I could substitute applesauce or mashed bananas for the sugar?
You could, yes, but the results won’t be quite the same without the sugar. If you’re looking to cut refined sugar, my Greek yogurt zucchini bread uses agave and you can use honey instead.
Can I use frozen zucchini and how much water do I squeeze out
Yes, you can use frozen zucchini. Thaw, then squeeze out most of the excess liquid.
I once made chocolate and zucchini cupcakes with raspberries; they were so good! I must try and recreate those cupcakes with this recipe: do you think I could add raspberries to the batter? How should I go about it, if I can? And how long should I bake them for as cupcakes? Thanks!
I would try gently folding in the raspberries at the end with the chocolate chip. See my recipe note for baking this as cupcakes!
Can i take out the zucchini?
Hi Jeannette! I don’t recommend it. Here is my regular chocolate cake recipe. https://route-span.live/triple-chocolate-layer-cake/%3C/p%3E
Can I use cake flour instead of all purpose flour
in this cake please?
Hi Heather! I don’t recommend cake flour; stick to all-purpose flour in this chocolate zucchini cake recipe.
Hi!
Would it be possible to leave out the choc chips? Where I stay, its really difficult to find good quality choc chips that dont taste like cheap chocolate and i’m scared they will ruin the flavour!
Thanks!
Hi Xenia! Yep, you can leave out the chocolate chips in this chocolate zucchini cake.
Hi Sally. Thank you for the awesome recipes. Will this cake hold its shape under fondant? Im thinking of using the recipe for a wedding cake
Yes! It should no problem.
When making cupcakes, how much do you put in the liners? I’ve made this recipe for two birthday cakes and they got rave reviews! A totally awesome recipe and my go to for chocolate cake. Thanks!
Hi Floyd! I fill the liners about 2/3 of the way full.