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Ultra Moist Chocolate Zucchini Cake

A rich, deeply chocolatey layer cake made extra tender with shredded zucchini and finished with creamy chocolate frosting.
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Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Servings: 12 slices
Course: Dessert
Cuisine: American
Calories: 412
Ingredients Equipment Method Notes

Ingredients
  

For the chocolate zucchini cake
  • 2 cups all-purpose flour
  • 3/4 cup unsweetened cocoa powder
  • 1 1/2 teaspoons baking soda
  • 1 teaspoon baking powder
  • 1/2 teaspoon salt
  • 1/2 cup vegetable oil
  • 1/2 cup sour cream
  • 1 cup granulated sugar
  • 1/2 cup light brown sugar
  • 2 large eggs
  • 2 teaspoons vanilla extract
  • 2 cups zucchini finely shredded, lightly packed
  • 1/2 cup buttermilk
  • 3/4 cup semisweet chocolate chips
For the chocolate frosting
  • 1/2 cup unsalted butter softened
  • 1/3 cup unsweetened cocoa powder
  • 2 1/2 cups powdered sugar
  • 1/4 cup heavy cream plus more as needed
  • 1 teaspoon vanilla extract
  • 1 pinch salt

Equipment

  • 2 8-inch round cake pans greased and lined
  • 1 mixing bowl medium
  • 1 mixing bowl large
  • 1 whisk
  • 1 spatula
  • 1 wire rack for cooling
  • 1 hand mixer for frosting

Method
 

Make the cake
  1. Preheat the oven to 350°F. Grease and line two 8-inch round cake pans with parchment paper.
  2. In a medium bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt.
  3. In a large bowl, whisk together the vegetable oil, sour cream, granulated sugar, brown sugar, eggs, and vanilla extract until smooth.
  4. Stir in the shredded zucchini and buttermilk.
  5. Add the dry ingredients to the wet ingredients and stir just until combined. Fold in the chocolate chips.
  6. Divide the batter evenly between the prepared pans and smooth the tops.
  7. Bake for 30 to 35 minutes, until the centers spring back lightly and a toothpick inserted in the middle comes out with a few moist crumbs.
  8. Cool the cakes in the pans for 15 minutes, then turn them out onto a wire rack and cool completely.
Make the frosting and assemble
  1. Beat the softened butter and cocoa powder until smooth.
  2. Add the powdered sugar, heavy cream, vanilla extract, and salt. Beat until fluffy, adding a little more cream if needed for a spreadable consistency.
  3. Place one cake layer on a serving plate and spread frosting over the top. Add the second cake layer, then frost the top and sides. Slice and serve.

Notes

Do not overmix the batter. Finely shred the zucchini and only lightly blot if very wet. Cool cake layers completely before frosting. For a sheet cake, bake in a 9x13-inch pan and begin checking around 35 minutes.