Chocolate zucchini cake is sweet and moist thanks to shredded zucchini. This sheet cake is topped with a luscious chocolate buttercream.

top of chocolate zucchini cake with chocolate frosting and half the cake cut into squares


 

You will never know there is zucchini in this chocolate cake. I mean, you can’t tell just by looking at these photos! This chocolate zucchini cake has a tender, moist texture thanks to the zucchini. The cake is also rich with chocolate flavor (just like my chocolate zucchini muffins). This recipe is the perfect use for any extra zucchini you may have growing in your garden this summer!

Why this recipe works: This recipe has a generous helping of zucchini (3 cups!), which provides extra moisture as well as some nutrition. You can make this cake in a 9×13 cake pan or two 9-inch round cake pans. Top it all off with my luscious chocolate buttercream frosting and you have a cake that I guarantee will be a hit this summer!

chocolate zucchini cake ingredients in bowls labeled with text

How to make chocolate zucchini cake

  1. Preheat oven to 350 F. Line a 9×13-inch baking pan with parchment paper and set aside.
  2. Whisk the dry ingredients together and set aside.
  3. Mix the wet ingredients together with an electric mixer until well combined. Add eggs one at a time, mixing well after each addition.
  4. Combine wet and dry ingredients. Mix just until combined, then stir in the shredded zucchini by hand. Transfer batter to prepared pan.
  5. Bake at 350 F for 30 to 35 minutes. Allow the cake to cool completely in the pan before frosting.
  6. Make chocolate buttercream frosting and frost the cooled cake.
photo collage demonstrating how to make chocolate zucchini cake in a mixing bowl and a 9x13 cake pan

Helpful tips

Cakes require careful measuring so I always use a kitchen scale. If you don’t have a kitchen scale, be sure to fluff up the flour with a fork and spoon it into a measuring cup (never pack down flour). It also helps to have room temperature ingredients. This allows everything to mix together smoothly for a consistent batter and ultimately a consistent cake texture.

The shredded zucchini requires a little bit of patting with a clean kitchen cloth or paper towels. However, you don’t want to pay it all the way dry! Leave a little moisture in the zucchini as it will help keep the cake moist too (I use this same method for my zucchini cupcakes).

To enhance the chocolate flavor, add 1/2 teaspoon espresso powder to the dry ingredients. I do this for most of my chocolate recipes. You can’t taste the coffee and it makes the chocolate taste richer and more intense.

chocolate zucchini sheet cake with chocolate frosting and half the cake cut into squares

Frequently Asked Questions

Do you peel zucchini for chocolate cake?

No. You don’t peel zucchini for chocolate cake. Shred the zucchini and discard the ends. The green skin actually provides the most nutrition!

Can I add chocolate chips to zucchini chocolate cake?

Yes, if you want more chocolate in this cake, add 1 cup chocolate chips or mini chocolate chips when stirring in the zucchini.

Can I make a layer cake with this recipe?

Yes, this cake can also be made in two 9-inch round cake pans. Baking time will be 20 to 25 minutes.

Can you freeze chocolate zucchini cake?

Yes, once the cake has completely cooled, wrap it in plastic wrap and aluminum foil. Freeze for up to 1 month. Defrost in the refrigerator overnight before bringing to room temperature and frosting. Alternatively, you can freeze individual slices of cake that have already been frosted.

square slice of chocolate zucchini cake with chocolate frosting

Zucchini is an incredibly versatile ingredient. Similar to this chocolate cake, my chocolate zucchini banana bread recipe proves that pairing chocolate with zucchini is always a good idea. I love adding zucchini to cakes and one of my personal favorites is this zucchini bundt cake with a cinnamon swirl as well as zucchini spice cake with cream cheese frosting. It’s a popular dessert to serve a crowd!

If you’re looking for an easy recipe, look no further than zucchini bread muffins. They are ready in under 30 minutes! My zucchini cookies are also ready in no time. You can also try these frosted zucchini brownies from Half Scratched blog.

square slice of chocolate zucchini cake on a white plate with fork holding a bite

Chocolate zucchini cake couldn’t be easier to make and it has all the flavor of a decadent chocolate dessert. I suggest making this cake next time you have friends over for dinner or when you’re going to a family get together. No one will believe there’s zucchini in the cake!

If you enjoyed this recipe, tap the stars to leave a review or leave a comment with feedback or questions. Remember to share your baking creations on social media by tagging @ifyougiveablondeakitchen.

tops of square slices of chocolate zucchini cake with chocolate frosting

Get the Recipe: Chocolate Zucchini Cake

Chocolate zucchini cake is sweet and moist thanks to shredded zucchini. This sheet cake is topped with a luscious chocolate buttercream.
5 (2 ratings)

Ingredients

Chocolate Zucchini Cake

  • 2 cups (250 g) all purpose flour
  • ยพ cup (72 g) unsweetened cocoa powder
  • 1 ยฝ teaspoons baking soda
  • ยฝ teaspoon baking powder
  • ยฝ teaspoon salt
  • ยพ cup (150 g) granulated sugar
  • ยพ cup (150 g) packed light brown sugar
  • ยพ cup vegetable oil
  • ยผ cup (56 g) unsalted butter, melted
  • ยผ cup sour cream, room temperature
  • 4 large eggs, room temperature
  • 1 teaspoon pure vanilla extract
  • 3 cups (330 g) shredded zucchini, patted slightly dry

Chocolate Buttercream

  • 1 cup (226 g or 2 sticks) unsalted butter, room temperature
  • 2 cups (240 g) confectioners' sugar, sifted
  • ยฝ cup (48 g) unsweetened cocoa powder
  • 1 teaspoon pure vanilla extract
  • 2-3 tablespoons milk, room temperature

Instructions 

Chocolate Zucchini Cake

  • Preheat oven to 350 F. Line a 9×13- inch baking pan with parchment paper and set aside.
  • In a large bowl, whisk together flour, cocoa powder, baking soda, baking powder and salt. Set aside.
  • In a separate large bowl, beat together granulated sugar, light brown sugar, vegetable oil, melted butter, sour cream and vanilla. Mix on medium-high speed until well combined, about 2 minutes. Add eggs one at a time, mixing well after each addition.
  • Pour wet ingredients into the bowl of dry ingredients. Use a rubber spatula to mix just until combined (avoid over mixing). Add shredded zucchini and stir just until incorporated.
  • Transfer batter to prepared pan and spread batter evenly. Bake at 350 F for 30 to 35 minutes or until a toothpick inserted in the center comes out with little to no crumbs. Allow the cake to cool completely in the pan before frosting.

Chocolate Buttercream Frosting

  • Using an electric mixer, beat the butter until fluffy, about 5 minutes.
  • Place the confectioners’ sugar and cocoa powder in a fine mesh strainer or sifter. Sift over the bowl with the butter. Beat on medium speed until combined. Add the vanilla and 2 Tablespoons milk, and beat for a minute, until fluffy. Add more milk if a thinner consistency is desired.
  • Transfer to a frosting bag with tip and frost away!Transfer frosting to cooled cake and use an offset spatula to spread evenly. Cut cake and serve.

Notes

Shredded zucchini should be slightly patted dry gently with a clean kitchen cloth or paper towel You want the zucchini to still have some moisture to provide to the cake.
Chocolate chips (1 cup) can be added to the cake when stirring in the zucchini.
Store chocolate zucchini cake covered in the refrigerator for up to 3 days.
Freeze unfrosted cake for up to 1 month. Let the cake cool completely, then wrap it in plastic wrap and aluminum foil to prevent freezer burn.
Recommended tools: kitchen scale, box grater, 9×13 cake pan, hand mixer or stand mixer, offset spatula
Serving: 1slice, Calories: 483kcal, Carbohydrates: 55g, Protein: 5g, Fat: 29g, Saturated Fat: 13g, Polyunsaturated Fat: 7g, Monounsaturated Fat: 7g, Trans Fat: 1g, Cholesterol: 87mg, Sodium: 311mg, Potassium: 249mg, Fiber: 3g, Sugar: 37g, Vitamin A: 613IU, Vitamin C: 4mg, Calcium: 48mg, Iron: 2mg

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