This chocolate zucchini cake is so rich and decadent you’ll forget there are healthy veggies baked inside!

square slice of chocolate zucchini cake sitting on a white round plate.

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Rich Chocolate Zucchini Cake Recipe

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 recipe that’s sweet, moist, and super chocolatey. It’s everything you want in a zucchini cake recipe and more!

This recipe is made with fresh zucchini and tangy sour cream, both of which make it supremely moist. Then, I use unsweetened cocoa powder to make the batter rich and chocolatey.

Next, I pour homemade ganache over the entire cake. You can never have enough chocolate! Chocolate and zucchini are a surprisingly delicious combination. Even the most ardent veggie haters in your family will devour this recipe!

square slice of chocolate zucchini cake sitting on a metal cake spatula.

Recipe Ingredients

To print: see recipe card below

For the Cake

  • 2 zucchini – One medium zucchini makes about 1 cup of grated, squeezed zucchini. 
  • 4 eggs – Let it come to room temperature for easy mixing.
  • 1/2 cup melted butter – I always recommend unsalted butter for baking!
  • 1/2 cup vegetable oil – Canola oil will work in place of vegetable oil. 
  • 1/2 cup sour cream – Use full-fat sour cream rather than low-fat or light versions.
  • 1 tablespoon vanilla extract
  • 2 cups flour – All-purpose flour forms the base of the cake.
  • 2 cups sugar
  • 2 teaspoons baking soda
  • 1 1/2 teaspoons baking powder
  • 2/3 cup unsweetened cocoa powder – Be sure to use unsweetened cocoa powder or Dutch process cocoa powder for a bold chocolate flavor.

For the Chocolate Ganache Frosting

  • 2 cups semisweet chocolate chips – Dark chocolate chips will also work in place of semisweet chocolate chips. 
  • 3/4 cup heavy cream


  • Skip the unsweetened cocoa powder and add ½ cup of flour to the recipe to make a classic zucchini cake.
  • Use a 1:1 gluten-free all-purpose flour to make a gluten-free zucchini cake. I have done this several times with great success!
  • Add ¾ cup of semisweet chocolate chips or mini chocolate chips to the cake batter for an extra chocolatey treat. I like to toss the chocolate chips in two tablespoons of flour to prevent them from sinking to the bottom as the cake bakes. 
  • Skip the ganache, and use chocolate frosting, cream cheese frosting, or powdered sugar instead.
ingredients to make chocolate zucchini cake.

Directions for How to Make Chocolate Zucchini Cake

  1. Prepare: Preheat your oven to 350ºF, and grease a 9×13 baking pan with cooking spray.
  2. Drain the zucchini: Use a box grater to shred the zucchini in a large bowl. Place the zucchini in a fine mesh sieve, and squeeze out any excess liquid. Then, transfer it to a large mixing bowl.
  3. Add the wet ingredients: Add the eggs, sour cream, butter, oil, and vanilla extract to the bowl with the zucchini, and mix well. 
  4. Add the dry ingredients: Stir in the dry ingredients until you have a smooth, thick batter. 
  5. Pour and bake: Pour the batter into the prepared pan, and bake until the center sets and the edges pull away from the pan.
  6. 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, and whisk to melt and combine.
  7. Ice the cake: Pour the melted ganache over the cake, spreading it into a smooth layer. 
  8. Cool and serve: Transfer the cake to the fridge, and cool completely to let the ganache set. Finally, slice, serve, and enjoy!

How to Store + Freeze

  • Store leftover chocolate zucchini cake in the fridge for up to one week. Transfer it to an airtight container, or wrap the slices tightly in plastic wrap.
  • Freeze unfrosted cake for up to three months. Wrap it tightly in plastic wrap followed by aluminum foil to keep it fresh.
  • Thaw the zucchini cake in the fridge overnight, add the frosting, and serve once it sets.

Quick Tip

Stay away from pre-grated zucchini. It may be tempting to grab the pre-grated stuff from the grocery store. However, it is likely treated with preservatives, which can affect how your cake bakes!

square slice of chocolate zucchini cake served on a white round plate with a forkful of cake.


Why use zucchini in baking?

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.

Why do you soak zucchini before cooking?

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!

Do you leave the skin on when you cook it?

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 most of the nutrients and fiber are found.

A slice of chocolate zucchini cake topped with ganache on a plate.

Chocolate Zucchini Cake

This chocolate zucchini cake is so rich and decadent, you'll forget there are healthy veggies baked inside!
5 from 1 vote
Course: Dessert
Cuisine: American
Servings: 16 servings
Prep Time: 15 minutes
Cook Time: 45 minutes
Total Time: 1 hour


  • 1 9×13 baking pan
  • 1 Box Grater
  • 2 Mixing bowls



  • 2 zucchini, grated and strained
  • 4 eggs
  • ½ cup melted butter
  • ½ cup sour cream
  • ½ cup vegetable oil
  • 1 Tablespoon vanilla extract
  • 2 cups flour
  • 2 cups sugar
  • 2 teaspoons baking soda
  • 1 ½ teaspoons baking powder
  • 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.
    2 zucchini, grated and strained
  • Add the eggs, melted butter, sour cream, oil, and vanilla to the zucchini bowl and stir everything together well.
    4 eggs, ½ cup melted butter, ½ cup vegetable oil, ½ cup sour cream, 1 Tablespoon vanilla extract
  • Add the flour, sugar, baking soda, baking powder, and cocoa powder to the bowl and stir to make a thick batter.
    2 cups flour, 2 cups sugar, 2 teaspoons baking soda, 1 ½ teaspoons baking powder, ⅔ cup unsweetened cocoa powder
  • 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.
    2 cups semi-sweet chocolate chips, ¾ cup heavy cream
  • 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!


You can skip the chocolate ganache if you’d like a lighter cake. It’s still sweet and delicious without the frosting!


Serving: 1serving | Calories: 417kcal | Carbohydrates: 52g | Protein: 6g | Fat: 22g | Saturated Fat: 13g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 6g | Trans Fat: 0.3g | Cholesterol: 74mg | Sodium: 209mg | Potassium: 339mg | Fiber: 4g | Sugar: 35g | Vitamin A: 506IU | Vitamin C: 5mg | Calcium: 64mg | Iron: 3mg
Did you make this recipe?Mention @kasey_allthingsmamma or tag #allthingsmamma!

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About Kasey Schwartz

For over 15 years, Kasey Schwartz, the mastermind behind All Things Mamma, has been the ultimate go-to for mouthwatering family recipes. Her work has been featured on, Buzz Feed, Better Homes and Gardens, and more, making her your go-to mom next door for all things delicious and family-friendly.


  1. Mary Ballah says:

    I have zucchini in the freezer and want to make the Chocolate Zucchini Cake. How much does the cake call for. One or two cups of zucchini.
    Thank you cake looks delicious 😊

5 from 1 vote (1 rating without comment)

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