Chocolate Zucchini Cake

chocolate zucchini cake

Triple Chocolate starts with a dark chocolate cake, dotted with pools of semi sweet chocolate chips, and smothered in fluffy chocolate buttercream. You won’t even know that this death by chocolate cake is filled with zucchini! This chocolate zucchini cake is rich, moist, tender, and the perfect blend of chocolate with a vegetable forward twist.

As you may know from my, Zucchini Ginger Spice Cake and Best Carrot Cake, I love using vegetables in cakes. Not only does it give the sweet treat a blast of nutrition, it makes for a standout, memorable dessert. Especially in this case where you’d never even realize you’re savoring zucchini in every vegetable laden bite of a decadent chocolate zucchini cake! Such a bonus to give kids a dessert with a side of veggies. Bea exclaimed that this was the best chocolate cake ever! I smiled to myself and felt very sneaky, ha!

So fellow bakers and tricksters, let’s get sneaky!


Zucchini is the unsung hero of this chocolate zucchini cake. This veggie is what gives the cake so much moisture without compromising any of that luxurious chocolate taste.

Use a box grater to shred the zucchini. Then set all of the shreds in a mesh strainer set over a sink or large bowl while you get to work on the batter. Since zucchini is about 90% water, Do not squeeze out all the moisture. Just let a little bit drain out. Or, after shredding onto a vegetable board, give it a light blot with a paper towel. This chocolate zucchini cake doesn’t have any milk or liquid. The moisture is coming from The zucchini, so you don’t want to remove all that water.

Zucchini is fairly tasteless so it is completely hidden within this chocolate zucchini cake. You can’t even see it! In fact, When I posted this cake on Instagram I forgot to even mention there was zucchini in this cake! Oops! Well now you know!

Oil vs. Butter

I usually go with all butter in my bakes. Here’s a quick break down of oil vs. butter and the reason this chocolate zucchini cake has an equal combo of both.

Oil is 100% fat. I find if you use all oil it can have a greasy effect that affects the taste of the cake. I have super sensitive taste buds, so I can call out canola in a heartbeat! The pros of using oil in a cake? First, it makes for a soft cake that doesn’t harden up in the fridge. Cakes made with oil will yield the “boxed cake” type texture. Second, it can make your batter a breeze to mix up since you skip the creaming process that you have with butter. Furthermore, if you’ve ever used oil based shortening in frosting, they spread and pipe like a dream. Also, oil doesn’t have that cholesterol that butter does.

Butter has about 80% fat. So what’s the difference? First, flavor, flavor, flavor! Did you get that it gives so much flavor to bakes like cakes? Second, butter based cakes won’t be as shiny. When refrigerated, it’s best to let it come to room temperature for maximum softener and fluffiness.

So now that we’ve cleared all that up, I used an equal combo of both canola oil and butter for this chocolate zucchini cake. Any oil taste is masked by all that chocolate, and you get all the softness and flavor of butter. It’s a win win!

Triple Chocolate

As I mentioned, this chocolate zucchini cake has three types of chocolate. The batter is made up of dark chocolate cocoa powder and semi sweet chocolate chips. The frosting is made with a milder chocolate cocoa. This gives you a triple threat of all kinds of chocolate power and flavor. It also makes for a gorgeous cake.

Chocolate Buttercream Frosting

This chocolate zucchini cake is finished off with my classic chocolate buttercream frosting. This frosting is the perfect chocolate frosting for any kind of cake or cupcake! See recipe below.

chocolate buttercream frosting

Now On To The Chocolate Zucchini Cake Recipe!

Chocolate Zucchini Cake

Triple Chocolate Zucchini Cake has dark chocolate cake with semi sweet chips and a light chocolate buttercream. You will never know there is zucchini in this rich and decadent cake!


Dry Ingredients

  • 2 cups AP Flour
  • 2/3 cup cocoa powder dark or regular
  • 1.5 tsp. baking soda
  • 1/2 tsp. baking powder
  • 1 tsp. salt

Wet Ingredients

  • 1/2 cup canola oil
  • 1/2 cup butter softened
  • 1.5 cups granulated sugar
  • 2 large eggs
  • 1 tablespoon vanilla extract
  • 1/2 cup sour cream
  • 2.5-3 cups zucchini grated and patted
  • 1 cup semi sweet chocolate chips


  1. Preheat oven to 350 degrees.

    Butter and lightly flour 2 8 inch pans.

    Whisk all of your dry ingredients in a bowl.

    Then use a whisk or a stand mixer to whisk together all of your wet ingredients. Start with butter and oil. Then you can add in the rest.

    Then use hand mixer on low/stir to incorporate the dry ingredients into the wet. 

    Fold in the chocolate chips and zucchini.

    Bake approx. 30 minutes until toothpick comes out clean.

    Let cool in pans for about 15 minutes before turning onto wire rack. Let cool completely before frosting.


Chocolate Buttercream Frosting

Fluffy, creamy, and full of chocolate! This buttercream frosting is the BEST!


  • 1.5 sticks butter unsalted
  • .5 stick salted butter
  • 3 or 3.5 cups powdered sugar pick your sweetness level
  • 1/2 cup cocoa powder
  • 1/4 cup whole milk or heavy cream
  • 1 tablespoon vanilla extract


  1. In a stand mixer, beat butter one minute. Then add in powdered sugar gradually while mixer is low, so it won't fly out. Add a tablespoon of milk and extract. Add cocoa powder. Next, add rest of milk. Beat on speed 8 until fluffy.

Recipe Notes

If you do not have both salted and unsalted butter, go with all unsalted then add in 1/4 teaspoon of salt. 

Tools For This Chocolate Zucchini Cake


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Earl Grey Cake

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