This chocolate zucchini cake combines indulgent chocolate cake layers packed with hidden zucchini (which you can’t taste!) with a decadent, silky avocado chocolate frosting for a healthy-ish treat no matter the occasion!
If you’re used to seeing zucchini recipes for fries, fritters, and stuffed with savory fillings, then mixing it into a cake might seem odd. But it helps to make a super moist, fudgy, dense (but not too dense) cake. This additional moisture is essential when working with gluten-free and vegan ingredients. Plus, I’m sure people also felt the same way about carrot cake, and look at how that turned out!
When combined with a rich, yet surprisingly healthy, chocolate ganache frosting (made from avocado!), this chocolate and zucchini cake is ready to become a new “healthier” favorite! It’s also dietarily adjustable, including gluten, dairy, gluten-free, and vegan options. It is the perfect cake recipe for sharing on almost any occasion!
Why You’ll Love This Chocolate Zucchini Cake Recipe
- It’s easy to make.
- Moist, decadent, fudgy – it’s the best zucchini cake recipe.
- The perfect amount of sweetness.
- Gluten-free and vegan (though no one can tell!), but works with regular flour and dairy if preferred.
- Packed with veggies – and you can’t even tell.
- Healthier than other chocolate cake recipes.
- Versatile – make this recipe into a layered cake, muffins/cupcakes, loaf cakes, or sheet cakes.
What Is Chocolate Zucchini Cake Made Of?
- Flour: I used a gluten-free flour blend (try Bob’s Red Mill, Better Batter, or King Arthur’s). However, regular all-purpose flour will work well if you aren’t gluten-free.
Avoid using a single gluten-free flour, like almond flour or coconut flour.
- Xanthan gum: This ingredient is only required if you use gluten-free flour.
- Sugar: Brown sugar adds a caramel-like flavor and moisture to the cake, though coconut sugar also works.
- Cacao powder: Use unsweetened cacao (or cocoa) powder.
- Leavening agents: This cake relies on baking powder and baking soda (learn the difference here) for lift.
- Salt: Just a pinch enhances the chocolate flavor in this healthy chocolate cake.
- Plant-based milk: I used oat milk, but any plant-based milk should work. Use dairy if you don’t want to make a vegan cake.
- Zucchini: Zucchini (young, smaller zucchini are best) is the special secret ingredient in this delicious chocolate cake recipe. It adds a ton of practically flavorless moisture (and nutrients!) and ensures a more tender crumb. Summer squash also works.
- Oil: To add extra moisture, I used coconut oil. Vegetable oil would also work.
- Flax eggs: Ground flaxseed and water mixture helps with binding.
- Coffee: brewed coffee (any type – including decaf, using espresso powder, etc.) will intensify the chocolate flavor. OR increase the zucchini to 2 cups and add 1 teaspoon of espresso powder.
- Apple cider vinegar: This will react with the leavening agents to help provide lift. Lemon juice or plain vinegar would also work.
- Vanilla extract: Use pure vanilla to avoid an artificial taste.
Chocolate Avocado Frosting
This frosting is free from all processed ingredients, refined sugars, trans fats, etc., for a healthy paleo and vegan chocolate frosting.
- Avocado: Use ripe to slightly over-ripe (but not too overripe) avocados.
- Milk: (optional)Use any dairy-free milk if needed to thin the frosting.
- Coconut oil: This will help achieve the correct consistency and a silky mouthfeel. Use refined coconut oil if you don’t want any coconut flavor. Vegan butter works too.
- Maple syrup: Or another liquid sweetener, like agave or a sugar-free alternative.
- Cocoa powder: Unsweetened cocoa powder (or cacao).
- Vanilla extract: Just a little for flavor depth.
- Salt: To enhance the flavor.
How to Make Chocolate Zucchini Cake
This healthy chocolate zucchini cake recipe is quick and easy to prepare. Just prepare the ingredients, mix the dry ingredients, add in the wet, bake, and frost – delish!
Prepare The Ingredients
First, grease or line two 8-inch round baking tins (I prefer spring-form pans for easy removal). Spray with cooking spray.
Start by combining the ground flaxseed and water, then set it aside to thicken for a few minutes. Also, combine the milk and apple cider vinegar and set aside.
Then, using a medium box grater (or grating disk on your food processor – this takes seconds!), grate the zucchini. No need to peel first.
Finally, combine the cacao powder and melted coconut oil in a medium bowl.
Mix and Bake The Batter
First, preheat the oven to 350 ºF/180C.
In a large mixing bowl, sift in all the dry ingredients and whisk the flour mixture to mix.
Then, carefully pour in all the wet ingredients, including the shredded zucchini (no need to remove the excess liquid first).
Stir the batter until well-incorporated, but make sure not to over-mix it. If using, now add chocolate chips/nuts.
If it seems a little stiff. Let it sit for a minute or two for the zucchini to release liquid and stir again.
Then, divide the chocolate zucchini cake batter between the prepared pans. Use a rubber spatula to help get all the batter from the bowl.
Next, transfer the pans to the oven and bake for between 40-45 minutes. Or until a toothpick inserted into the center of each cake comes out clean-ish (moist crumbs are fine, but no wet batter).
Transfer the cakes to a wire cooling rack and leave them to cool completely. Then, carefully slice each cake in half to make four layers (unless you baked them in 3-4 pans separately).
Frost The Chocolate Zucchini Cake
To prepare the chocolate avocado frosting, blend all the ingredients in a small blender or food processor. Start without the milk and then add to thin the frosting to your desired consistency. Then taste and adjust any of the ingredients to your liking.
With the cakes cooled, liberally spread the frosting between the layers, decorate the top, slice, and enjoy!
You could replace it with additional plant-based milk. The cake won’t have such a rich chocolate depth or complex flavor, but it will still be delicious.
Yes, you could use 2 large eggs (at room temperature) instead of the flax eggs. You can also use dairy milk in the recipe.
No! You can’t see or taste the zucchini in this chocolate cake. Instead, it just adds moisture and extra nutrients.
You can replace some of the oil with unsweetened applesauce (or some plain yogurt/sour cream if not vegan). But I don’t recommend replacing it all, as it reduces the moisture.
Cocoa powder and Dutch process cocoa contain different acidity levels (the first being acidic and the second being a neutral base). This means they’ll react differently to the leavening agents. For that reason, I can’t guarantee results.
More Cake Recipes
- Quick and Easy Peach Dump Cake
- No-Bake Chocolate Cake with Caramel (Mars Cake)
- Blood Orange Cake with Pistachios
- Fluffy Homemade Coconut Cream Cake
- Chocolate Mug Cake
- Easy Rhubarb Crisp Recipe
If you try this chocolate zucchini cake recipe, let me know how it goes in the comments below. I’d appreciate a recipe card rating and would love to see your recipe recreations – tag me on Instagram @Alphafoodie!
Super Moist Chocolate Zucchini Cake
- 2.5 cups gluten-free flour like Bob's Red Mill, King Arthur's, or Better Batter; regular all-purpose flour will also work
- 1/2 teaspoon Xanthan gum only needed if you're using gluten-free flour
- 1.5 cups brown sugar or coconut sugar
- 1 cup cacao powder unsweetened; or cocoa powder (less bitter but more processed)
- 2 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 2 cups oat milk or any other milk: dairy or dairy-free
- 1 cup zucchini shredded
- 3/4 cup coconut oil melted; or vegetable oil
- 2 vegan flaxseed eggs 2 tablespoon ground flaxseed in 1/3 cup water
- 1/2 cup brewed coffee OR increase the zucchini to 2 cups and use 1 teaspoon of espresso powder
- 2 Tbs[ apple cider vinegar or lemon juice
- 2 teaspoon vanilla extract
- 1.5 avocados
- 1/2 cup almond milk optional – if needed to thin the frosting; can also use any dairy or dairy-free milk
- 1/4 cup coconut oil or butter/vegan butter
- 1/3 cup maple syrup or another liquid sweetener: agave syrup, etc.
- 2 tablespoon cacao powder unsweetened
- 1/2 tablespoon vanilla extract
- ⅛ teaspoon salt
- 2 Baking dish 8-inch round each
Prepare The Ingredients
- Grease or line two 8-inch round baking tins (I prefer spring-form pans for easy removal) and spray with cooking spray.
- Combine the ground flaxseed and water, then set it aside to thicken for a few minutes. Also, combine the milk and apple cider vinegar and set aside.
- Use a medium box grater (or grating disk on your food processor – this takes seconds!) to grate the zucchini – no need to peel first.
- Combine the cacao powder and melted coconut oil.
Mix and Bake The Batter
- Preheat the oven to 350ºF/180ºC.
- In a large mixing bowl, sift in all the dry ingredients and whisk the flour mixture to mix.
- Carefully pour in all the wet ingredients, including the shredded zucchini (no need to remove the excess liquid first).
- Stir the batter until well-incorporated, but make sure not to over-mix it. If using, now add chocolate chips/nuts.If it seems a little stiff, let it sit for a minute or two for the zucchini to release liquid and stir again.
- Divide the cake batter between the prepared pans, using a rubber spatula to help get all the batter from the bowl.
- Transfer the pans to the oven and bake for between 40-45 minutes, or until a toothpick inserted into the center of each cake comes out clean-ish (crumbs are fine, but no wet batter).
- Transfer the cakes to a wire cooling rack and leave them to cool completely. Then, carefully slice each cake in half to make four layers.
Frost The Cake
- To prepare the chocolate avocado frosting, blend all the ingredients together in a small blender or food processor. Start without the milk and then add to thin the frosting to your desired consistency. Taste and adjust any of the ingredients to your liking.
- With the cakes cooled, liberally spread the frosting between the layers, decorate the top (optional), slice, and enjoy!
- Make ahead: It's best to prepare the frosting fresh, but you can prepare the cake 1-2 days in advance, ready to frost before serving.Store: If you use the avocado frosting, the color and texture will be best on the day it's made. However, you can store the frosted cake in an airtight container in the fridge for 2-3 days.Freeze: It's best to freeze the cake unfrosted. Wrap it in two layers of plastic wrap, then transfer it to a freezer-safe bag for up to 3 months. Then thaw at room temperature, frost, and enjoy.
- To save time: Depending on how thick you’d prefer each layer, divide the mixture into three or four pans and reduce the baking time accordingly.
- Bake immediately after mixing: The leavening agents will get to work immediately, so don’t let the batter sit for too long before baking the cakes.
- The frosting: Double the amount, if needed, to generously frost four cake layers, including the top of the cake.
- For cupcakes: I recommend halving the batter quantities and dividing it between cupcake liners. Reduce the baking time accordingly to between 18-24 minutes.
- For loaf cakes/sheet cakes: Divide the batter between loaf pans/sheet pans and bake, using a toothpick to test for doneness at 30 minutes (40 for loaf) and every few minutes after.
- Using regular vs. gluten-free flour: The former will be slightly moister and less dense.
- Don’t over-mix the batter: It can affect the results and lead to tough, gummy, dense baking.
- Chocolate chip zucchini cake: I love adding (½-1 cup of) semi-sweet chocolate chips (dark chocolate) for a triple chocolate cake with chocolate chips.
- Nuts: Add ½ cup of chopped nuts like walnuts, pistachios, hazelnuts, etc., for texture and crunch.
- Cinnamon: A little (1 tsp) will add depth.
- Another frosting: If you’d prefer a richer cake, use a chocolate ganache, buttercream frosting, or cream cheese frosting (dairy or vegan).
- Toppings: You can sprinkle the cake with cocoa powder, fresh berries, chopped nuts, shredded coconut, grated chocolate, or even a little whipped coconut cream.