Chocolate Zucchini Cake

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You’re about to be obsessed with this easy Chocolate Zucchini Cake! The three super moist chocolate cake layers are full of zucchini and frosted with delicious chocolate buttercream. Every bite is totally decadent!

Why You’ll Love This Recipe

• Incredible texture. I seriously can’t get enough of how moist and tender this cake is! It might just give my moist chocolate cake a run for its money. It is SUCH a treat to bite into.
• Chocolate-full. Between the rich chocolate cake layers and the velvety smooth chocolate buttercream, this zucchini chocolate cake is a chocolate lover’s dream.
• A great way to use zucchini. This recipe is one of the best uses for zucchini I have ever made. It makes the cake layers so moist, and you won’t even know it’s there!
• Super easy mixing method. This cake batter is so easy to make! Just combine the dry ingredients, combine the wet ingredients, and put it all together. You got this!

Ingredient Notes

Here’s what you’ll need to make this chocolate zucchini cake recipe. Scroll on down to the recipe card below for precise measurements.

Chocolate Zucchini Cake

• All-purpose flour –  I highly suggest using the spoon and level method or a food scale to get the proper amount of flour here. Otherwise, you’ll have a dry, dense cake.
• Natural unsweetened cocoa powder – You can use Dutch-processed cocoa powder instead if you’d like a richer chocolate flavor.
• Baking soda – Be sure not to use baking powder. Baking soda gives the cake the best texture.
• Salt – Without a little salt, you’ll have a bland cake.
• Unsalted butter (melted) and vegetable oil – I used both in this cake. The butter adds a richness that the vegetable oil alone doesn’t. The oil adds moisture that butter alone can’t provide.
• Granulated sugar and light brown sugar – The brown sugar deepens the flavor of the cake layers and contributes some extra moisture.
• Vanilla extract
• Eggs – Be sure to use large eggs, not medium or extra large.
• Sour cream – Full fat sour cream is best. The sour cream adds acidity needed for the cake to rise properly.
• Milk – I generally use 2%, but whole milk would also work.
• Hot water – The hot water works to bloom the cocoa powder, bringing out its full chocolate flavor potential.
• Shredded zucchini – Check out the section below titled “What’s The Best Way to Shred Zucchini?”.

Chocolate Buttercream

• Unsalted butter – Start with room temperature butter. If it is too cold, the frosting will turn out lumpy. If it is melted, you’ll find yourself with runny frosting.
• Powdered sugar – The powdered sugar not only sweetens the buttercream but also helps to stabilize it and add volume.
• Natural unsweetened cocoa powder – Dutch-processed cocoa powder will also work if you want a richer chocolate flavor.
• Vanilla extract
• Heavy cream
• Salt – To balance out the sweetness of the frosting a bit and accentuate the flavor a bit.
• Mini chocolate chips – These are optional but I like to use them to decorate the bottom half of the cake.

What’s The Best Way to Shred Zucchini?

I suggest grating your zucchini with a box grater. I set it over a bowl and grate the zucchini into it. No need to peel the zucchini here! It’s often suggested to squeeze out excess water, but I did not. My zucchini didn’t feel like it was full of excess moisture. If yours does, pat it dry. And be careful with your fingers! Box graters can be dangerous things, if you aren’t careful.

How to Make Chocolate Zucchini Cake

Here’s a quick overview of how to make this moist zucchini-loaded chocolate cake. Be sure to scroll to the recipe card below for more detailed instructions.

• Prep. Line the bottom of three 8-inch cake pans with parchment paper and grease the sides. Preheat oven to 350°F.
• Combine the dry ingredients. Whisk together the flour, cocoa powder, baking soda, and salt.
• Combine the wet ingredients. Mix together the butter, vegetable oil, sugars, and vanilla. Whisk in the eggs and sour cream followed by the milk.

• Put it all together. Mix the dry ingredients into the wet ingredients and then mix in the hot water. Fold in the zucchini.

• Bake. Divide the batter between the cake pans and bake for 28-33 minutes.
• Cool. Allow the cakes to cool in their pans for a few minutes before turning them out onto cooling racks.
• To make the frosting. Beat the butter until smooth. Mix in 3 cups of powdered sugar along with the cocoa powder. Mix in the vanilla and 3 tablespoons of heavy cream followed by the remaining powdered sugar.

• Adjust the consistency. Add more heavy cream (if needed) to get the right consistency.
• Layer. Remove the domes from the cake layers and place one layer on a serving platter. Spread 3/4 cup frosting over the top and then add another cake layer. Repeat. Frost the outside of the cake.
• Decorate. Decorate how you like! I will often press mini chocolate chips into the bottom half of the sides of the cake and sprinkle a few on top.

Tips for Success

• Don’t over-mix. When combining the wet and dry ingredients and when folding the zucchini into the batter, don’t mix more than you have to. Over-mixing can cause the glutens in the flour to overdevelop, which can give you tough, overly dense cake layers.
• HOT water. The water you add to the cake batter should be piping hot. The high temperature wakes up the cocoa powder, enhancing the chocolate flavor.
• Room-temperature butter. The butter in the frosting should be at room temperature. If it is too cold, the buttercream will turn out lumpy. If it is melted, you’ll find yourself with runny frosting. So let it sit out on the counter for an hour or two before making the frosting.
• Make it pretty. You don’t have to be a master cake decorator to make this cake look pretty, but I do suggest you take a look at my tutorials on how to level a cake and how to stack a cake. They’ll set you in the right direction.

How to Store This Cake

• Counter/refrigerator: Seal the cake in an airtight container or wrap it in a double layer of plastic wrap. If you go the plastic route, use toothpicks to prop it away from any decorations. You can also slice the cake and arrange slices in a single layer in an airtight container. Store the cake at room temperature for up to 24 hours or in the fridge for up to 4 days.
• Freezer: Pop the cake in the freezer to firm up. After a couple of hours, wrap the whole thing in a double layer of plastic wrap. Alternatively, arrange slices in a single layer in an airtight container. You can store leftovers in the freezer for up to 3 months. Allow it to thaw in the fridge before serving.

More Chocolate Cake Recipes

• Mint Chocolate Cake
• Flourless Chocolate Cake
• German Chocolate Cake
• Orange Chocolate Cake
• Red Wine Chocolate Cake
• The Best Chocolate Cake Recipe

Watch How to Make it

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