This Chocolate Zucchini Cake is moist, tender, and full of deep chocolate flavor. It’s easy to prepare—no mixer required—and finished with a silky chocolate ganache. The zucchini keeps the cake surprisingly moist while remaining undetectable, making this a perfect way to add a little extra nutrition to a classic dessert.
Baking with zucchini is one of my favorite ways to boost moisture and nutrition in sweet treats. It works beautifully in quick breads, muffins, and cakes—especially this chocolate zucchini cake. The grated zucchini blends into the batter so well that even picky eaters won’t notice it.
This recipe is straightforward and forgiving. The cake has a tender crumb and rich chocolate notes, and the simple three-ingredient ganache creates an irresistible, fudgy topping. It’s a great summer dessert and an excellent way to use up an abundance of zucchini from the garden.
Chocolate Zucchini Cake: Ingredients & Substitutions
- Butter and oil: The recipe uses 1/4 cup melted butter and 1/4 cup canola oil for a balance of buttery flavor and moist texture. You can use 1/2 cup butter or 1/2 cup oil if you prefer. Coconut oil or ghee are possible alternatives.
- Sour cream: Greek yogurt can be substituted for sour cream for a similar texture.
- Sugar: Granulated sugar is used here, but organic cane sugar or brown sugar will also work.
- Flour: All-purpose flour is standard. You can replace up to half with white whole wheat or whole wheat pastry flour. A cup-for-cup gluten-free baking flour also works.
- Espresso powder: Espresso powder enhances chocolate flavor but instant coffee can be used if needed.
- Chocolate chips: Mini chocolate chips give the best small pockets of chocolate throughout the cake. Regular chips are fine if that’s what you have.
How to Make Chocolate Zucchini Cake
This recipe is simple and quick to assemble. Read through the steps before you start, and have your grated zucchini measured and ready.
1. In a medium bowl, whisk together the dry ingredients: flour, unsweetened cocoa powder, baking soda, baking powder, sea salt, and espresso powder. Setting the dry mix aside ensures even distribution in the batter.
2. In a large bowl, combine the melted butter, canola oil, sour cream, eggs, and vanilla. Whisk until smooth. Add the granulated sugar and whisk again until the sugar is incorporated and the mixture feels uniform.
3. Add the dry ingredients to the wet ingredients and stir with a spatula or whisk until the batter is smooth and even. Avoid overmixing.
4. Fold the shredded zucchini and mini chocolate chips into the batter with a spatula, distributing them evenly without overworking the mix.
Bake & Cool
Spread the batter into a greased 8×8 or 9×9-inch baking pan (or into a 9-inch round pan). Bake at 350°F (177°C) for 25–30 minutes, or until the edges are set and a toothpick inserted in the center comes out clean.
Cool the cake on a wire rack to room temperature before topping, or refrigerate to speed the process.
Pan type
This cake can be baked in an 8×8 or 9×9 square dish, a single 9-inch round pan, or split into two 6-inch round pans for a double-layer cake. An 8×8 pan may take slightly longer to bake than a 9×9.
Make the Ganache
Warm 1 cup heavy cream over medium heat, stirring every 30 seconds. When the edges begin to bubble and steam rises, remove from heat just before a full rolling boil.
Add 1 cup chocolate chips or chopped chocolate and 1/4 teaspoon vanilla to the hot cream. Whisk until smooth and slightly thickened. Let the ganache cool a bit while you stir gently so it thickens to a pourable but spreadable consistency.
Assemble
Pour the slightly cooled ganache over the cooled cake and spread it evenly with a spatula. Smooth the surface for a glossy finish.
Chill
Refrigerate the cake for at least 3 hours so the ganache sets firmly. If you opt for a different frosting (for example, a no-chill buttercream), you can serve the cake immediately.
Serve
Slice the cake into 9–16 pieces. It’s excellent slightly chilled; serve with a scoop of vanilla ice cream or a dollop of whipped cream for an extra treat.
To freeze slices, place chilled pieces on a baking sheet lined with wax paper and freeze until firm (3–4 hours). Wrap each slice in plastic wrap and store in an airtight container in the freezer.
Store
Keep leftover cake covered in an airtight container in the refrigerator for up to 5 days.
Freeze
To freeze the whole cake, wrap it tightly with plastic wrap and foil (or use a pan with a lid) and freeze for up to two months. Thaw in the refrigerator before serving.
Chocolate Zucchini Cake Recipe FAQs
Common questions about this recipe:
This cake works in a 9×9 or 8×8 square pan, a 9-inch round pan, or two 6-inch round pans for a layered cake. Expect slightly longer baking time in an 8×8 pan.
No. Keep the skin on—the skin contains nutrients and blends into the batter.
Yes. Any frosting you prefer can be used. If it doesn’t require chilling, you can serve the cake right away.
Yes. Double the ingredients and bake in a 9×13-inch pan or in two 9-inch round pans.
Zucchini adds moisture and a bit of nutrition to baked goods without changing the flavor—an easy way to make treats a little healthier.
If you try this recipe, I’d love to hear how it turned out—leave a comment and rating if you wish. Enjoy!
Chocolate Zucchini Cake
Author: Laura Sandford
A moist, rich chocolate cake made with shredded zucchini and finished with a smooth chocolate ganache.
Course: Dessert
Cuisine: American
Servings: 16
Calories: 284 per serving (approx.)
Prep Time: 20 minutes | Cook Time: 30 minutes | Chilling: 3–4 hours | Total Time: 4 hours 50 minutes
Equipment
- Measuring spoons and cups
- Mixing bowls
- Spatula and whisk
- Box grater or food processor for shredding zucchini
- 8×8 or 9×9-inch baking pan (or 9-inch round)
- Wire cooling rack
Ingredients
Cake
- 1 cup shredded zucchini
- ¼ cup salted butter, melted
- ¼ cup canola oil
- ¼ cup sour cream (or Greek yogurt)
- 2 eggs, beaten
- 1 teaspoon pure vanilla extract
- ¾ cup granulated sugar
- 1 cup all-purpose flour
- ¼ cup unsweetened cocoa powder
- 1 teaspoon baking soda
- ¼ teaspoon baking powder
- ½ teaspoon fine sea salt
- ½ teaspoon espresso powder (optional)
- ½ cup mini chocolate chips
Chocolate Ganache
- 1 cup heavy whipping cream
- 1 cup chocolate chips or chopped chocolate
- ¼ teaspoon vanilla extract
Instructions
- Preheat oven to 350°F (177°C). Grease an 8×8 or 9×9-inch baking pan or a 9-inch round pan.
- In a medium bowl, whisk together flour, cocoa powder, baking soda, baking powder, sea salt, and espresso powder. Set aside.
- In a large bowl, whisk melted butter, oil, sour cream, eggs, and vanilla until combined. Add sugar and whisk until smooth.
- Add the dry ingredients to the wet ingredients and mix until the batter is smooth.
- Fold in shredded zucchini and mini chocolate chips with a spatula until evenly distributed.
- Spread batter in the prepared pan and bake for 25–30 minutes, until the sides are set and a toothpick inserted in the center comes out clean.
- Cool the cake on a rack to room temperature or chill in the refrigerator.
- To make ganache: warm heavy cream until it begins to bubble around the edges. Remove from heat and whisk in chocolate and vanilla until smooth. Allow to cool slightly.
- Pour ganache over the cooled cake and spread evenly. Refrigerate for at least 3 hours until the ganache is set.
- Slice and serve. Store leftovers in an airtight container in the refrigerator for up to 5 days.
Notes
- Nutrition facts are approximate and calculated per serving when the recipe yields 16 pieces.
- Feel free to substitute ingredients as noted in the substitutions section above.
- To double the recipe, bake in a 9×13-inch pan or split between two 9-inch round pans.
Nutrition (approx.)
Serving: 1 piece | Calories: 284 | Carbohydrates: 27 g | Protein: 3 g | Fat: 19 g | Saturated Fat: 9 g | Cholesterol: 52 mg | Sodium: 199 mg | Fiber: 2 g | Sugar: 17 g
Try these recipes
Chocolate Zucchini Brownies
Best Zucchini Bread
Zucchini Bars
Double Chocolate Zucchini Bread
Chocolate Chip Zucchini Cookies
