This chocolate zucchini cake is so rich and decadent, you’ll forget there are healthy veggies baked inside!
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It’s amazing how the humble zucchini can be transformed into delicious baked goods like Zucchini Bread and Zucchini Carrot Bars. Even then, you probably wouldn’t describe these recipes as decadent—but you haven’t tried this chocolate zucchini cake recipe.
I mean, just look at this cake! You’d never guess we’re sneaking in veggies, right?
The best part of this recipe is how easy it is to make such a decadent chocolate cake. All you really need is to measure, mix, and bake for a chocolate zucchini cake that’s sweet, moist, and super chocolatey. It’s everything you want in a zucchini cake recipe and more!
Rich Chocolate Zucchini Cake Recipe
I have always loved making zucchini bread, but why not take that classic zucchini bread (or Chocolate Zucchini Bread!) and turn it into something sweeter and more dessert-worthy? I decided to take on this challenge and try my hand at making the best chocolate zucchini cake ever.
This chocolate zucchini cake recipe is made with fresh zucchini and tangy sour cream, both of which make it supremely moist. I use unsweetened cocoa powder to make the cake rich and chocolatey. Then, I pour homemade ganache over the entire cake. You can never have enough chocolate! And chocolate and zucchini are a surprisingly delicious combination—even the most ardent veggie haters in your family will devour this cake.
Ingredients for Chocolate Zucchini Cake
See recipe card below this post for ingredient quantities and full instructions.
- Zucchini – One medium zucchini makes about 1 cup of grated, squeezed zucchini.
- Butter – Use unsalted butter when making this zucchini cake recipe.
- Vegetable oil – Canola oil will also work in place of vegetable oil.
- Sour Cream – Use full-fat sour cream rather than low-fat or light versions.
- Baking soda
- Baking powder
- Unsweetened cocoa powder – Be sure to use unsweetened cocoa powder. The darker the chocolate, the better!
- Heavy cream
- Semisweet chocolate chips – Dark chocolate chips will also work in place of semisweet chocolate chips.
Try these ingredient substitutions and variations:
- Skip the unsweetened cocoa powder and add ½ cup of flour to the recipe to make a classic zucchini cake with chocolate frosting.
- Use gluten-free all-purpose baking mix to make a gluten-free zucchini cake. I have done this several times with great success!
- Add ¾ cup of semisweet chocolate chips to the zucchini cake batter for an extra chocolatey cake. I like to toss the chocolate chips in 2 tablespoons of the flour to help prevent them from sinking to the bottom as the cake bakes.
Stay away from pre-grated zucchini. It may be tempting to grab the pre-grated stuff from the grocery store, but it is likely treated with preservatives, which may affect how your cake bakes.
How to Make Chocolate Zucchini Cake
- Prepare: Preheat your oven to 350ºF and use baking spray to grease a 9×13 baking pan.
- Drain the zucchini: Grate the zucchini into a large bowl, then place it in a fine mesh sieve. Press the zucchini into the sieve to extract the liquid. Squeeze as much water out of the zucchini as possible, then transfer it to a large mixing bowl.
- Add the wet ingredients: Add the eggs, sour cream, butter, oil, and vanilla extract to the bowl with the zucchini and mix well.
- Add the dry ingredients: Mix in the dry ingredients until you have a thick batter.
- Pour and bake: Pour the batter into the cake pan, then bake for about 55 minutes. The cake will be set in the center and pulling away from the edges of the pan. Let the cake cool in the pan.
- Make the ganache: Add the chocolate chips to a large bowl, then bring the heavy cream to a boil in a pot. Pour the hot cream over the chocolate chips, then whisk to melt the chocolate and stir it into the cream.
- Ice the cake: Pour the melted ganache over the cake and spread it into a smooth layer.
- Cool and serve: Place the cake in the fridge for about 15 minutes to chill the ganache and make it easy to cut. Then, slice and serve your chocolate zucchini cake!
How to Store Chocolate Zucchini Cake
Chocolate zucchini cake is very moist, so it needs to be stored in the fridge. Wrap your zucchini cake in plastic wrap and keep it in the fridge for up to one week.
Chocolate zucchini cake freezes very well. Skip the ganache topping, wrap the cake tightly in plastic wrap, then freeze for up to three months. Let the cake thaw in the fridge overnight, then make the frosting right before you’re ready to serve. The chocolate zucchini cake will taste as good as the day it was baked!
Zucchini adds a lot of moisture to baked goods. It helps cakes, muffins, and breads stay very tender and dense. Zucchini is also quite nutritious and will help improve your baked goods from a nutritional standpoint as well.
Zucchini can become mushy quite quickly. Soaking it in cold water will prevent this. Soft zucchini is actually good for our zucchini chocolate cake, so there is no need to soak the veggies for this recipe!
I keep the skin on the zucchini when I grate it. The skin is very thin and will not alter the taste or texture of your zucchini cake. It’s also where a lot of the veggie’s nutrients are found, so it makes your cake healthier.
Chocolate Zucchini Cake
- 2 zucchini, grated and strained
- 4 eggs
- ½ cup melted butter
- ½ cup vegetable oil
- ½ cup sour cream
- 1 tablespoon vanilla extract
- 2 cups flour
- 2 cups sugar
- 2 teaspoons baking soda
- 1 ½ teaspoons baking powder
- ⅔ cup unsweetened cocoa powder
Chocolate Ganache Frosting
- 2 cups semi-sweet chocolate chips
- ¾ cup heavy cream
- Preheat your oven to 350 degrees F and spray a 9×13 baking pan with baking spray.
- Grate the zucchini with the skin on. Press the grated zucchini in a fine mesh sieve, extracting the liquid. Discard the liquid and put the squeezed, grated zucchini in a large mixing bowl.
- Add the eggs, melted butter, sour cream, oil and vanilla to the zucchini bowl and stir everything together well.
- Add the flour, sugar, baking soda, baking powder and cocoa powder to the bowl and stir to make a thick batter.
- Spread the batter in the greased pan and bake for 55 minutes. A toothpick inserted into the center of the cake will come out cleanly.
- Let the cake cool in the pan while you make the frosting.
- Add the chocolate chips to a large mixing bowl. Bring the heavy cream to a boil in a small pot. The moment the cream starts to boil, remove it from the stovetop and pour it into the bowl of chocolate chips.
- Let the chocolate chips sit in the heavy cream for one minute then stir, melting the chocolate completely and incorporating it into the heavy cream to make a thick, creamy glaze.
- Pour the chocolate ganache into the pan with the zucchini cake, spreading the frosting over the cake evenly.
- Place the cake in the fridge to chill for 15 minutes, just to set the ganache and make it sliceable.
- Cut and serve the chocolate zucchini cake!