Recipe – Chocolate Zucchini Cake

This chocolate zucchini cake is super moist, rich, and packed with deep chocolate flavor. It’s made with 3 cups of shredded zucchini—but don’t worry, you won’t see or taste the veggies! The cake is topped with smooth chocolate buttercream frosting for a delicious finish. Even picky eaters won’t know they’re eating vegetables!

Why You’ll Love This Cake

Moist, soft, and super chocolatey
Easy to make with simple ingredients
A great way to use up extra zucchini
You can’t taste the zucchini at all
Covered in rich chocolate buttercream
Works as a layer cake, sheet cake, or cupcakes

Ingredients

For the 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 vanilla extract
3 cups (about 360g) shredded zucchini (lightly blotted – see tip below)
1 cup (180g) semi-sweet chocolate chips (regular or mini)

For the Chocolate Buttercream:

1 and 1/4 cups (282g) unsalted butter, softened
3 and 1/2 cups (420g) powdered sugar
3/4 cup (62g) unsweetened cocoa powder
3–5 tablespoons (45–75ml) heavy cream, milk, or half-and-half
1/4 teaspoon salt
1 teaspoon vanilla extract
Optional: chocolate chips or sprinkles for decorating

Instructions

1. Prep the Oven & Pans:

Preheat your oven to 350°F (177°C).
Grease two 9-inch round cake pans.
Line the bottoms with parchment paper, then grease the paper too.

2. Mix Dry Ingredients:

In a large bowl, whisk together flour, cocoa powder, baking soda, baking powder, espresso powder (if using), and salt.

3. Mix Wet Ingredients:

In another bowl, use a mixer to beat oil, both sugars, eggs, sour cream, and vanilla until well combined.
Add the shredded zucchini and mix again.

4. Combine:

Slowly add the dry mixture into the wet mixture and mix until combined.
Stir in the chocolate chips. The batter will be thick.

5. Bake:

Divide the batter between the two pans.
Bake for 28–32 minutes, or until a toothpick inserted comes out clean.
Let cakes cool in the pans for 1 hour, then transfer to a wire rack to cool completely.

6. Make the Frosting:

Beat the butter until creamy (about 2 minutes).
Add powdered sugar, cocoa powder, 3 tablespoons of cream, salt, and vanilla.
Beat slowly at first, then faster until smooth.
Add more cream if frosting is too thick, or more sugar if it’s too thin. Taste and adjust salt if needed.

7. Assemble the Cake:

Use a knife to level the top of each cake layer.
Place one layer on your serving plate and spread frosting on top.
Add the second layer and cover the top and sides with the rest of the frosting.
Use extra frosting for piping and decorate with sprinkles or chocolate chips.

Tips & Tricks:

Lightly blot the zucchini with a towel—don’t squeeze too much moisture out, just a little.
For a sheet cake, use a 9×13-inch pan and bake for about 45 minutes.
To make cupcakes, fill liners 3/4 full and bake at the same temp for 18–22 minutes.
You can make the cake and frosting a day ahead. Store the cake covered at room temp; keep frosting in the fridge and bring to room temp before using.
The frosted or unfrosted cake can be frozen for up to 2 months. Thaw overnight in the fridge.

Quick Recipe Summary

Description:

A rich, soft, and super chocolatey zucchini cake topped with creamy chocolate buttercream. You’ll never believe there are 3 cups of zucchini inside!

Duration:

Prep time: 30 minutes
Bake time: 30 minutes
Cooling & Assembly: 90+ minutes
Total time: About 2.5 hours

Ingredients (Short List)

Cake:

2 cups all-purpose flour
3/4 cup unsweetened cocoa powder
2 tsp baking soda
1/2 tsp baking powder
1 tsp espresso powder (optional)
1/2 tsp salt
1 cup vegetable oil
1 cup granulated sugar
3/4 cup brown sugar
4 eggs
1/3 cup sour cream or plain yogurt
2 tsp vanilla extract
3 cups shredded zucchini
1 cup chocolate chips

Frosting:

1 1/4 cups butter
3 1/2 cups powdered sugar
3/4 cup cocoa powder
3–5 tbsp cream or milk
1/4 tsp salt
1 tsp vanilla extract