When zucchini season is in full swing, there’s only so much grilled zucchini and zucchini bread you can make before you’re looking for something a little more exciting. It’s a little more than chocolate zucchini bread. It’s Chocolate Zucchini Cake! Rich, moist and deeply chocolatey, it’s the kind of dessert that proves zucchini belongs just as much in chocolate cake as it does in savory recipes. In fact, most people would never guess there’s a vegetable hidden inside!

The shredded zucchini practically disappears into the batter as it bakes, adding incredible moisture without changing the flavor. The result is a tender chocolate cake that’s soft, fudgy and impossible to resist. It’s topped with an old-fashioned cooked chocolate frosting made with chocolate chips and marshmallows that melts into a glossy, creamy layer over the warm cake.

Why You’ll Love This Recipe

It’s a wonderfully moist and tender homemade chocolate cake.
It’s an excellent way to use fresh zucchini.
There is rich chocolate flavor in every bite.
It’s an easy one-layer chocolate sheet cake.
There is an old-fashioned chocolate marshmallow frosting.
It’s perfect for potlucks, parties and family gatherings.
No one will ever guess there’s zucchini inside!

ingredients displayed for making chocolate zucchini cake

Ingredients You’ll Need

For the Cake

All-purpose flour
Unsweetened cocoa powder
Baking soda
Salt
Shredded zucchini
Granulated sugar
Vegetable or canola oil
Vanilla extract

The zucchini adds moisture while the oil keeps the cake rich and tender.

For the Chocolate Marshmallow Frosting

Unsalted butter
Granulated sugar
Milk
Semisweet chocolate chips
Mini marshmallows
Vanilla extract

This old-fashioned cooked frosting is silky, fudgy and wonderfully nostalgic.

six photos showing how to make chocolate zucchini cake

Recipe Tips

Don’t peel the zucchini: The peel is tender and blends right into the cake, adding color and nutrients without affecting the texture.
Don’t squeeze out the moisture: Unlike some zucchini recipes, this cake benefits from the zucchini’s natural moisture. Simply shred it and add it directly to the batter.
Measure the zucchini after shredding: You’ll need 2 cups of shredded zucchini, lightly packed.
Frost while the cake is still slightly warm: The frosting spreads beautifully over a slightly warm cake and creates a glossy finish.
Make Ahead Instructions: This cake is even better the next day.
Bake it one day ahead, cover tightly and store at room temperature or refrigerate until serving.
Storage Tips: Store covered at room temperature for up to 3 days or refrigerate for up to 5 days. The cake also freezes beautifully. Wrap individual slices or the entire cake tightly and freeze for up to 2 months.

Variations

Add chocolate chips: Fold a cup of semisweet or dark chocolate chips into the batter for even more chocolate flavor.
Add espresso powder: A teaspoon of instant espresso powder intensifies the cocoa flavor without making the cake taste like coffee.
Add chopped nuts: Walnuts or pecans add delicious crunch and pair beautifully with chocolate.
Make cupcakes: Divide the batter among cupcake liners and reduce the baking time to about 18 to 22 minutes.

chocolate zucchini cake in baking pan with slice taken out

What to Serve with Chocolate Zucchini Cake

This cake is delicious with:

Vanilla ice cream
Fresh whipped cream
Fresh raspberries
Strawberries
Cold milk
Coffee
Hot chocolate

It’s also perfect for:

Summer picnics
Birthday parties
Potlucks
Bake sales
Family reunions

slices of chocolate zucchini cake overhead shot

Frequently Asked Questions

Can you taste the zucchini?

Not at all. The zucchini simply adds moisture while the rich chocolate flavor takes center stage.

Should I peel the zucchini?

No. The peel softens as the cake bakes and isn’t noticeable in the finished cake.

Do I need to drain the zucchini?

No. The moisture from the zucchini helps create the cake’s wonderfully tender texture.

Can I use frozen zucchini?

Yes. Thaw it first and gently drain any excess liquid before measuring.

Can I make this into a Bundt cake?

Yes, although the baking time will increase. Check for doneness after about 50 to 60 minutes.

Can I freeze Chocolate Zucchini Cake?

Absolutely. It freezes very well and tastes just as moist after thawing.

Why This Recipe Works

The combination of shredded zucchini and oil creates an incredibly moist chocolate cake that stays soft for days. Cocoa powder provides rich chocolate flavor while the cooked marshmallow frosting adds an old-fashioned touch that’s both fudgy and silky. Because the zucchini blends seamlessly into the batter, it enhances the texture without changing the flavor, making this one of the best ways to use up summer zucchini.