This Double Chocolate Zucchini Cake is super moist and extra chocolate-y. It’s topped with homemade chocolate frosting — because who doesn’t love to eat chocolate on chocolate? 

frosted chocolate zucchini cake slice on white plate next to glass of milk

Easy Zucchini Dessert Recipe

Have you ever tried chocolate zucchini cake? You don’t taste the zucchini at all, and instead you end up with the most delicious chocolate cake that’s moist with a soft, dense cake crumb.

Growing up, one of my favorite recipes was my mom’s simple chocolate cake. It was moist, not too rich, topped with chocolate buttercream, and perfect for children. She’d decorate it with candies for our birthdays, and I was always thrilled when she made it.

So when she told me one afternoon that she was making chocolate zucchini cake, I wasn’t impressed. The idea of vegetables in cake seemed wrong, and I felt she was ruining my favorite recipe. But after tasting the chocolate zucchini cake, I had to swallow my words (along with some cake). Because chocolate zucchini cake is delicious. So moist and full of chocolate goodness! I was converted.

overhead view of chocolate zucchini cake slice on white plate with glass of milk

What’s Needed for Double Chocolate Zucchini Cake?

For the zucchini cake itself, you’ll need the following ingredients: 

  • All-purpose flour
  • Cocoa powder
  • Baking powder
  • Baking soda
  • Salt 
  • Vegetable oil
  • Granulated sugar
  • Light brown sugar
  • Eggs
  • Vanilla extract
  • Sour cream
  • Shredded zucchini

And to make the BEST chocolate buttercream frosting, you’ll need: 

  • Unsalted butter
  • Cocoa powder
  • Heavy cream or milk
  • Powdered sugar

slice of chocolate zucchini cake on white plate next to glass of milk

How to Make Chocolate Zucchini Cake

The zucchini cake itself and the chocolate buttercream frosting are a breeze to make! Here’s how we make this chocolate zucchini cake with homemade chocolate frosting: 

  1. Start by beating together the oil, sugar, eggs, vanilla, sour cream, and shredded zucchini.
  2. Then, whisk together the dry ingredients, then beat them into the wet mixture. Easy as that!
  3. After everything’s mixed together, pour the batter into a 9×13-inch pan and bake.
  4. Once the cake has cooled completely, top with homemade chocolate frosting. 

bowl of homemade chocolate frosting with knife resting on top

Does Zucchini Cake Have to be Refrigerated?

No, this double chocolate zucchini cake does not have to be refrigerated, but it will keep for up to a week in the refrigerator.

Can You Freeze Zucchini Cake?

Yes! To freeze, simply wrap the zucchini cake tightly with aluminum foil or plastic freezer wrap, or place in heavy-duty freezer bag. This double chocolate zucchini cake will keep 2-3 months in the freezer. You can freeze the cake frosted or unfrosted, and the frosting freezes well by itself too! 

slice of frosted chocolate zucchini cake on white plate next to glass of milk

Tips for Making Chocolate Zucchini Cake

For the shredded zucchini, if you find there’s excess liquid you can gently soak it up with a paper towel. Just make sure it isn’t dry when adding to the cake.

I also recommend shredding the zucchini using the finest side of your box grater. This way, you won’t bite down on any big chunks of zucchini by mistake. 

The homemade chocolate frosting is a simple frosting recipe made with cocoa powder. However, I like to add a little cream cheese to cut the sweetness. If you don’t have cream cheese on hand, you can easily substitute it with more butter too as specified in the recipe. 

More Zucchini Dessert Recipes: 

More EASY CAKE RECIPES You Have to Try:

Double Chocolate Zucchini Cake

Double Chocolate Zucchini Cake

3.65 from 34 votes
Servings: 18
Prep Time: 10 minutes
Cook Time: 35 minutes
Total Time: 45 minutes


This Double Chocolate Zucchini Cake is super moist and extra chocolate-y. It's topped with homemade chocolate frosting — because who doesn't love to eat chocolate on chocolate? 


For the Chocolate Zucchini Cake:

  • 1 1/3 cups all-purpose flour
  • 3/4 cup unsweetened cocoa powder
  • 2 teaspoons baking powder
  • 1 teaspoon baking soda
  • 1/4 teaspoon salt
  • 2/3 cup vegetable oil, (or canola oil)
  • 1 cup granulated sugar
  • 3/4 cup brown sugar, , packed
  • 3 large eggs
  • 2 tsp vanilla extract
  • 1/4 cup sour cream
  • 2 cups shredded zucchini

For the Chocolate Frosting:

  • 3/4 cup unsalted butter, , softened
  • 2/3 cup usweetened cocoa powder
  • 3-4 cups powdered sugar, , sifted
  • 4-6 tablespoons heavy cream, (or milk)


For the Chocolate Zucchini Cake:

  • Preheat the oven to 350F degrees, then butter and flour a 9x13-inch baking pan.
  • In a large bowl, sift together the flour, cocoa, baking powder, baking soda and salt.
  • In a separate large bowl using an electric mixer, beat together the oil, sugars, eggs and vanilla.
  • Turn the mixer down to low speed, then carefully beat in the sour cream followed by the flour mixture.
  • Stir in the shredded zucchini.
  • Pour the batter into the prepared pan and bake for 30-35 minutes or until an inserted toothpick comes out clean.

For the Chocolate Frosting:

  • Beat the butter in a large bowl until very soft.
  • Beat in 2 cups of powdered sugar, followed by the cocoa powder.
  • Beat in the rest of the powdered sugar, about 1/2 cup at a time alternating with 1 tablespoon of the heavy cream.
  • Frost the cooled cake with a flat edge knife.


May be stored at room temperature for 2-3 days.


Serving: 1gCalories: 295kcalCarbohydrates: 50gProtein: 3gFat: 11gSaturated Fat: 7gPolyunsaturated Fat: 1gMonounsaturated Fat: 3gTrans Fat: 1gCholesterol: 54mgSodium: 113mgPotassium: 142mgFiber: 1gSugar: 40gVitamin A: 345IUVitamin C: 1mgCalcium: 45mgIron: 1mg
Author: Fiona
Course: Easy Cake Recipes For Beginners
Cuisine: American

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