Rich Chocolate Zucchini Cake with Whipped Cream Frosting

If you ask me, chocolate cake is always a good idea—even when it’s hiding vegetables.

This moist chocolate cake sneaks in shredded zucchini for extra moisture without any veggie taste. Rich cocoa and a hint of espresso give it deep chocolate flavor, while the zucchini keeps every slice tender.

It’s topped with a light whipped cream frosting that’s sweetened with powdered sugar and cocoa. The frosting is smooth and airy, a nice contrast to the soft cake.

It’s a dessert that works for summer when zucchini is everywhere, and nobody will guess there’s a green vegetable baked right in.

What Kind of Zucchini Should I Use?

For this chocolate cake, you’ll want to use smaller to medium-sized zucchini rather than the giant ones you sometimes see at the farmers market. The smaller zucchini tend to have fewer seeds and a more tender texture, which means they’ll blend right into your cake without anyone noticing. You don’t need to peel the zucchini – the skin is thin and will practically disappear once it’s shredded and baked into the batter. After shredding, there’s no need to squeeze out the moisture like you might for other recipes, since that liquid actually helps keep your cake nice and moist.

Options for Substitutions

This cake is pretty forgiving when it comes to swaps, so here are some options if you need them:

• Buttermilk: No buttermilk? Mix 1 cup of regular milk with 1 tablespoon of lemon juice or white vinegar and let it sit for 5 minutes. You can also use plain yogurt thinned with a bit of milk.
• Zucchini: Yellow squash works just as well as zucchini in this recipe. Make sure to squeeze out excess moisture with a clean kitchen towel before adding it to the batter, regardless of which you use.
• All purpose flour: You can use a 1:1 gluten-free flour blend if needed, though the texture might be slightly different. Whole wheat flour works too, but use half whole wheat and half all-purpose for better results.
• Heavy whipping cream: For the frosting, you really need heavy cream to get that whipped texture – there’s no good substitute here. Light cream or milk just won’t whip up properly.
• Granulated sugar: You can replace up to half the granulated sugar with brown sugar for a deeper flavor, but keep at least half as white sugar for the right texture.

Watch Out for These Mistakes While Baking

The biggest mistake people make with zucchini cake is not squeezing out the excess moisture from the shredded zucchini, which can lead to a dense, wet cake that takes forever to bake through – use a clean kitchen towel or cheesecloth to wring out as much liquid as possible before adding it to the batter.

When making the whipped cream frosting, be careful not to overbeat it or you’ll end up with butter instead of fluffy frosting, so stop mixing as soon as stiff peaks form.

Since this cake is quite moist, it’s important to let it cool completely before frosting, otherwise the whipped cream will melt and slide right off.

For the best texture, make sure to properly measure your flour by spooning it into the measuring cup and leveling it off rather than scooping directly from the bag, which can pack in too much flour and result in a dry cake.

What to Serve With Chocolate Zucchini Cake?

This cake is pretty rich and decadent on its own, so I like to keep things simple when serving it. A scoop of vanilla ice cream on the side is always a good call, especially if you serve the cake slightly warm – the contrast between cold ice cream and warm cake is really nice. Fresh berries like raspberries or strawberries add a nice pop of brightness that cuts through the chocolate, and they look pretty on the plate too. If you’re serving this for a crowd, set out some coffee or cold milk since chocolate cake and milk is a combo that never gets old.

Storage Instructions

Store: Keep your chocolate zucchini cake covered in the fridge since it has whipped cream frosting. It’ll stay fresh for about 3-4 days in an airtight container or covered with plastic wrap. The cake actually tastes even better the next day once the flavors have had time to settle in together.

Freeze: You can freeze the unfrosted cake layers wrapped tightly in plastic wrap and then foil for up to 3 months. I don’t recommend freezing the whipped cream frosting though, as it doesn’t hold up well in the freezer and can get watery when thawed.

Serve: Let the cake sit at room temperature for about 15-20 minutes before serving if it’s been in the fridge. This brings out the chocolate flavor and makes the texture nice and moist again.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 3400-3700
• Protein: 40-50 g
• Fat: 160-180 g
• Carbohydrates: 450-480 g

Ingredients

For the cake:

• 2 cups sugar
• 1 cup buttermilk
• 2 eggs (room temperature, about 70°F for better emulsion)
• 1 1/2 tsp vanilla
• 2 1/4 cups flour (I always use King Arthur all-purpose flour)
• 3/4 cup cocoa powder (sifted to remove lumps)
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp salt
• 3 cups zucchini (shredded and squeezed well to remove excess moisture)
• 1/2 tsp instant espresso powder

For the frosting:

• 1 1/2 cups heavy cream (I prefer Land O’Lakes for a stable whip)
• 3/4 cup powdered sugar
• 3 tbsp cocoa powder
• 1 1/2 tsp vanilla
• 1/4 tsp instant espresso powder

Step 1: Prepare Pan and Mix Dry Ingredients

• 2 1/4 cups flour
• 3/4 cup cocoa powder
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp salt
• 1/2 tsp instant espresso powder

Preheat your oven to 350°F and grease a 9×13 inch baking dish or similar size cake pan.

While the oven heats, sift together the flour, cocoa powder, baking soda, baking powder, salt, and instant espresso powder in a medium bowl.

Sifting the cocoa is crucial here—it removes lumps and ensures even chocolate distribution throughout the cake.

Set this dry mixture aside.

Step 2: Prepare Zucchini and Create Wet Mixture

• 3 cups zucchini
• 2 cups sugar
• 1 cup buttermilk
• 2 eggs
• 1 1/2 tsp vanilla

While the oven continues heating, shred your zucchini and place it in a clean kitchen towel or cheesecloth.

Squeeze it firmly to remove as much excess moisture as possible—this is essential because too much water will make your cake dense and soggy.

In a large mixing bowl, whisk together the sugar, buttermilk, room temperature eggs, and vanilla until well combined and slightly pale.

I always use room temperature eggs because they emulsify better with the other ingredients, creating a more tender crumb.

Step 3: Combine Wet and Dry, Add Zucchini

• dry ingredient mixture from Step 1
• wet ingredient mixture from Step 2
• prepared zucchini from Step 2

Add the dry ingredient mixture from Step 1 to the wet mixture from Step 2, stirring gently with a spatula until just combined—don’t overmix, as this can develop gluten and make the cake tough.

Fold in the squeezed zucchini until evenly distributed throughout the batter.

The batter should be thick and chocolatey with visible zucchini pieces.

Step 4: Bake the Cake

• combined batter from Step 3

Pour the batter into your prepared pan and spread it into an even layer.

Bake at 350°F for 30-35 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs (not wet batter).

The cake will continue to set slightly as it cools.

Remove from the oven and let it cool completely in the pan at room temperature—this usually takes about an hour.

Step 5: Prepare Whipped Cream Frosting

• 1 1/2 cups heavy cream
• 3/4 cup powdered sugar
• 3 tbsp cocoa powder
• 1 1/2 tsp vanilla
• 1/4 tsp instant espresso powder

While the cake cools, prepare your frosting.

In a clean, cold mixing bowl, combine the heavy cream, powdered sugar, cocoa powder, vanilla, and instant espresso powder.

I always use heavy cream from quality brands like Land O’Lakes because it whips to a more stable, luxurious texture.

Start beating on medium speed and gradually increase to medium-high, beating until stiff peaks form.

Be careful not to overbeat or you’ll end up with butter—stop as soon as the peaks hold their shape.

Step 6: Frost and Serve

• cooled cake from Step 4
• whipped cream frosting from Step 5

Once the cake has cooled completely, spread the whipped cream frosting evenly over the top using an offset spatula or the back of a spoon.

For a prettier presentation, create gentle swirls or peaks in the frosting.

Slice and serve immediately, or refrigerate for up to a few hours if needed—the whipped cream frosting is best enjoyed fresh but will hold well chilled.

Rich Chocolate Zucchini Cake with Whipped Cream Frosting

Delicious Rich Chocolate Zucchini Cake with Whipped Cream Frosting recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings: 12 slices

Calories: 3550

Ingredients Method

Ingredients

  

For the cake:

• 2 cups sugar
• 1 cup buttermilk
• 2 eggs (room temperature, about 70°F for better emulsion)
• 1 1/2 tsp vanilla
• 2 1/4 cups flour (I always use King Arthur all-purpose flour)
• 3/4 cup cocoa powder (sifted to remove lumps)
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp salt
• 3 cups zucchini (shredded and squeezed well to remove excess moisture)
• 1/2 tsp instant espresso powder

For the frosting:

• 1 1/2 cups heavy cream (I prefer Land O'Lakes for a stable whip)
• 3/4 cup powdered sugar
• 3 tbsp cocoa powder
• 1 1/2 tsp vanilla
• 1/4 tsp instant espresso powder

Method

 

1. Preheat your oven to 350°F and grease a 9x13 inch baking dish or similar size cake pan. While the oven heats, sift together the flour, cocoa powder, baking soda, baking powder, salt, and instant espresso powder in a medium bowl. Sifting the cocoa is crucial here—it removes lumps and ensures even chocolate distribution throughout the cake. Set this dry mixture aside.
2. While the oven continues heating, shred your zucchini and place it in a clean kitchen towel or cheesecloth. Squeeze it firmly to remove as much excess moisture as possible—this is essential because too much water will make your cake dense and soggy. In a large mixing bowl, whisk together the sugar, buttermilk, room temperature eggs, and vanilla until well combined and slightly pale. I always use room temperature eggs because they emulsify better with the other ingredients, creating a more tender crumb.
3. Add the dry ingredient mixture from Step 1 to the wet mixture from Step 2, stirring gently with a spatula until just combined—don't overmix, as this can develop gluten and make the cake tough. Fold in the squeezed zucchini until evenly distributed throughout the batter. The batter should be thick and chocolatey with visible zucchini pieces.
4. Pour the batter into your prepared pan and spread it into an even layer. Bake at 350°F for 30-35 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs (not wet batter). The cake will continue to set slightly as it cools. Remove from the oven and let it cool completely in the pan at room temperature—this usually takes about an hour.
5. While the cake cools, prepare your frosting. In a clean, cold mixing bowl, combine the heavy cream, powdered sugar, cocoa powder, vanilla, and instant espresso powder. I always use heavy cream from quality brands like Land O'Lakes because it whips to a more stable, luxurious texture. Start beating on medium speed and gradually increase to medium-high, beating until stiff peaks form. Be careful not to overbeat or you'll end up with butter—stop as soon as the peaks hold their shape.
6. Once the cake has cooled completely, spread the whipped cream frosting evenly over the top using an offset spatula or the back of a spoon. For a prettier presentation, create gentle swirls or peaks in the frosting. Slice and serve immediately, or refrigerate for up to a few hours if needed—the whipped cream frosting is best enjoyed fresh but will hold well chilled.