This is literally the best chocolate zucchini cake in the history of ever. So fluffy, so moist, so perfectly chocolatey. It’s amazing!

It is also the main reason I plant zucchini in my garden year after year.

Even when those zucchini squash grow to baseball bat-size proportions, they work for this best-ever cake (just peel off the tough skin, scrape out the seeds and finely shred the zucchini).

A piece of chocolate cake with a large dollop of whipped chocolate frosting on top.

It Starts with Zucchini

Zucchini squash is absolutely necessary for the outcome of this cake.

So if you’re looking for a substitution, the only one I can suggest in good conscious is yellow squash. It can usually be interchanged with recipes that call for shredded zucchini.

This recipe calls for two cups of shredded zucchini. Finely shredding it gives the cake the best texture.

While many recipes call for squeezing out the liquid in shredded zucchini, it’s not necessary in this recipe unless you are using frozen, shredded zucchini. Once it is thawed, it will have quite a bit more liquid to it; drain that watery liquid off before using.

Liquid measuring cup filled to the two cup line with shredded zucchini.

Straightforward Cake Batter

Other than the shredded zucchini, the ingredients for this cake batter are pantry and fridge staples.

The zucchini is mixed with the wet ingredients and then the dry ingredients are added.

Mix just until the dry ingredients are incorporated. Kind of like a good muffin batter, you don’t want to over mix this cake batter much or else the cake crumb might not be as soft and fluffy.

Mixing shredded zucchini into cake batter; mixing flour and cocoa powder into cake batter.
Stirring chocolate zucchini cake batter with rubber spatula.

Bake, Cool, Frost

The cake bakes up like a dream. Slightly puffed in the center and soft and tender throughout.

I don’t bother flipping the cake out of the pan or frosting it in any kind of elegant way, shape or form.

This is a casual, rustic cake. We’re here for the ultimate effect of zucchini on chocolate cake (read: it’s amazing) and not for any persnickety purposes.

Baked chocolate zucchini cake in metal 9X13-inch pan.

Frosting for Chocolate Zucchini Cake

My favorite frosting adornment for this cake is a simple, lightly sweetened chocolate whipped cream. I literally just throw into a blender: heavy cream, a bit of powdered sugar, cocoa powder until it feels right, and a bit of vanilla. And then blend until thick and creamy.

The pillow chocolate whipped cream with the fluffy, moist, decadent cake is an amazing combination.

Of course you can also dig into the cake straight out of the pan, no frosting necessary. It almost feels kind of breakfast-y that way. And none of my eyes will judge you for it.

Or a classic chocolate frosting does quite well, also.

A fork sticking into a piece of chocolate cake with whipped chocolate frosting.

I know there are a million things you can do with your zucchini crop (not the least of which are these baked zucchini bites and of course my go-to zucchini bread), but seriously, this chocolate cake wins them all.

This cake recipe comes from my Aunt Marilyn. It is a tried-and-true family favorite and has been for years and years. Nothing can beat it.

I wait all year for zucchini season. Which I guess, in a way, could really just be renamed: chocolate zucchini cake season.

A piece of chocolate cake with a bite taken out and chocolate whipped frosting on top.

The Best Chocolate Zucchini Cake

4.62 stars (223 ratings)


  • 3 large eggs
  • 1 tablespoon vanilla extract
  • 1 ½ cups (318 g) granulated sugar
  • ¾ cup buttermilk (see note)
  • ½ cup (113 g) melted coconut oil, avocado oil, canola oil or vegetable oil
  • 2 cups (283 g) finely shredded zucchini
  • 1 ½ cups (213 g) all-purpose flour
  • ½ cup (43 g) natural, unsweetened cocoa powder
  • ¾ teaspoon salt
  • 1 teaspoon baking soda
  • ¼ teaspoon baking powder


  • Preheat the oven to 350 degrees F. Lightly grease a 9X13-inch pan with cooking spray and set aside. I always use an aluminum/metal baking pan.
  • In a large bowl, whisk together the eggs, vanilla, sugar, buttermilk and oil.
  • Stir in the shredded zucchini.
  • Add the flour, cocoa powder, salt, soda and baking powder.
  • Stir until just combined and no dry streaks remain.
  • Spread the batter evenly in the pan and bake for 25-35 minutes until the top springs back lightly to the touch and a toothpick comes out clean or with a few moist crumbs.
  • Let cool completely.
  • Serve with a dollop of lightly sweetened chocolate whipped cream (see note) or spread with chocolate frosting and cut into squares.


Zucchini: I don’t squeeze any excess liquid out of the zucchini for this recipe; however, previously frozen, shredded zucchini tends to be a bit more liquidy so if using thawed zucchini that’s been frozen, you might drain slightly.
Frosting: this cake is delicious all by itself! But it’s also super tasty with chocolate frosting or my favorite, lightly sweetened chocolate whipped cream. For the cream, combine 1 1/2 cups heavy whipping cream, 1/3 cup powdered sugar, 1/3 cup cocoa powder (Dutch-process cocoa powder is delicious here but you can use natural, unsweetened too), 1/2 teaspoon vanilla. Whip until thick and creamy.
Bundt Pan: my Aunt Marilyn says this recipe works great in a bundt pan – bake for about 45-50 minutes.
Buttermilk: here are some buttermilk substitutions if you don’t have buttermilk on hand.
Serving: 1 Serving, Calories: 217kcal, Carbohydrates: 32g, Protein: 4g, Fat: 9g, Saturated Fat: 7g, Cholesterol: 34mg, Sodium: 224mg, Fiber: 1g, Sugar: 21g

Recipe Source: adapted slightly from my Aunt Marilyn (I reduce the sugar from 2 cups to 1 1/2 cups, as well as reducing the oil a bit, and use buttermilk instead of milk)