Chocolate Zucchini Cake

A slice of frosted chocolate cake on a plate.

5 from 1 vote

The secret to moist, irresistible chocolate cake? Add zucchini! Chocolate zucchini cake is made with two layers of rich chocolate cake that's topped with fluffy chocolate buttercream frosting.

Prep Time20

Cook Time28

Resting time1

Total Time1 48

Servings: or more

Calories: 470kcal

Ingredients

Cake

2 cups (300 g) finely grated zucchini, do not drain liquid out
1 ¾ cups (345 g) granulated sugar
¾ cup (150 g) vegetable oil
3 large eggs, room temperature
2 teaspoons vanilla extract
2 cups (240 g) all-purpose flour
¾ cup (63 g) natural cocoa powder
1 teaspoon baking powder
1 teaspoon baking soda
½ teaspoon salt

Frosting

1 cup (227 g) unsalted butter, room temperature
3 cups (342 g) confectioner's sugar
½ cup (40 g) natural cocoa powder
⅓ cup (76 g) heavy cream, cold
⅛ teaspoon salt
2 teaspoons vanilla extract

Instructions

Cake

Preheat oven to 350℉. Grease two 8-inch or 9-inch round cake pans, line the bottoms with parchment circles, and set aside.
In a large bowl, add finely grated zucchini (including any excess liquid), granulated sugar, oil, eggs, and vanilla extract. Stir until evenly combined.
In a separate bowl, whisk together dry ingredients: flour, cocoa powder, baking soda, baking powder, and salt. Add to wet ingredients and stir until just combined.
Pour batter evenly between your two prepared round cake pans. Gently tap on the countertop to remove air bubbles.
Two 9 inch round cake pans: 26-30 minutes
Two 8 inch round cake pans: 28-34 minutes
Bake your cake using the time frames above as a reference.
To test for doneness: Is your cake jiggly in the center? It needs more time. If it's not jiggly, gently press the top of the cake. If an indent is left, it needs more time. if it pops back, the cake is done. Cake temperature can also be tested with an instant-read thermometer. It's done when it reaches 210F in the center.
Remove cake from oven and allow to cool completely in the pan(s) on a wire cooling rack.

Frosting

Meanwhile, in a large bowl, add butter. Using a hand mixer or stand mixer, beat until fluffy, about a minute.
Add confectioner's sugar and cocoa powder, half at a time, and slowly mix until ingredients are incorporated. Then, whip at high speed for 1 to 2 minutes, or until light and fluffy.
Add heavy cream, salt, and vanilla extract and whip an addition 1 to 2 minutes, or until light and fluffy.
Gently flip and remove cooled cakes from their pans. Trim the rounded tops with a serrated knife to make flat layers.
Place one layer, top side down, onto a cake stand or serving plate. Top with frosting and spread into an even layer. Add second layer of cake, top side down, and top with another layer of frosting. Spread remaining frosting onto the sides of the cake.

Recommended Equipment

Notes

Nutrition: estimate is calculated for 16 slices of cake.
To make a single layer sheet cake: this recipe can be baked in a 9x13 baking pan for about 32-38 minutes, or a 13x18 half sheet pan for about 18-20 minutes.
Frosting: Recipe makes enough frosting to thinly coat the middle, top, and sides as shown in the photos.
Want a less sweet frosting? Try an ermine frosting or whipped cream instead. Reducing the sugar in buttercream results in a greasy, lightly-sweetened butter rather than a frosting.
Storage: Homemade cake is best served the same day for best moisture and texture. Leftovers will keep for 2-3 days at room temperature, 3-4 days in the refrigerator, or up to 3 months in the freezer. Refrigerated cake needs to come to room temperature for 1 hour before serving, and frozen cake needs 2-3 hours to come to room temperature before serving.

Nutrition Estimate

Course: Dessert

Cuisine: American