Moist Chocolate Zucchini Cake
Bake the best Chocolate Zucchini Cake from scratch with cacao, fresh zucchini, and a rich chocolate buttercream frosting. A moist, decadent dessert made with whole real foods—no boxed mixes here!
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While I grow zucchini in my garden and love enjoying it fresh, I’ve always treated zucchini as a year-round veggie. In the summer, I grill it; in the spring, I sauté it; and in the fall and winter (okay, let’s be honest—anytime) I love adding it into cozy cakes! This moist Chocolate Zucchini Cake is one of my all-time favorites. Not just a favorite zucchini cake—one of my favorite cakes, period.
If you’ve never baked with zucchini before, you’ll be amazed at how it disappears into the batter, leaving behind the most incredible fudgy, moist texture without tasting like vegetables. This recipe is made completely from scratch with whole, real ingredients—no boxed mixes or shortcuts. And to make it truly irresistible, I finish it with my homemade Chocolate Buttercream Frosting for the ultimate decadent dessert.
Rich, indulgent, and unbelievably moist, this is a cake you’ll find yourself baking again and again.
Why You’ll Love This Chocolate Zucchini Cake
- Super Moist: The grated zucchini adds amazing texture and keeps the cake soft for days.
- Rich & Chocolatey: Made with cacao powder for a deep, robust chocolate flavor.
- Real Ingredients: A combination of butter, olive oil, and homemade sour milk gives it a tender crumb.
- Family Favorite: Even kids who claim they don’t like zucchini love this cake.
- Versatile: Works for birthdays, potlucks, or just an everyday treat.
Key Ingredients
- Zucchini – Finely grated, skin on, and don’t strain. The natural moisture is what makes the cake so soft.
- Cacao Powder – I prefer cacao over cocoa because it’s less processed and has a deeper flavor.
- Butter + Olive Oil – Butter adds richness while olive oil helps keep the cake tender.
- Sour Milk – Easily made at home with whole milk and a splash of lemon juice.
- Sugar – Sweetens and balances the deep chocolate notes.
- Eggs + Vanilla – For structure and flavor.
- Flour, Baking Soda & Salt – The base of the cake with just enough lift.
- Chocolate Chips – Sprinkled on top for extra indulgence.
Cocoa Powder vs. Cacao Powder
You’ll often see recipes call for cocoa powder, but I personally prefer cacao powder. Here’s why:
- Cocoa powder is roasted at higher temperatures, which gives it a slightly milder, sweeter flavor.
- Cacao powder is less processed and made from fermented, dried cacao beans. It retains more nutrients and has a stronger, richer chocolate flavor.
- Both can be used in baking, but cacao powder gives this cake a bold, dark-chocolate taste that really stands out.
If you only have cocoa powder on hand, you can absolutely use it—but if you can get cacao, (I get mine at THRIVE MARKET) it makes the cake extra special.
Step-by-Step Instructions for this Chocolate Zucchini Cake
- Make sour milk: Stir 1 tablespoon of lemon juice into ½ cup of whole milk. Set aside for 5 minutes.
- Cream butter, oil, and sugar: In a large mixing bowl, beat together 12 tablespoons butter, ¼ cup olive oil, and 1¾ cups sugar until light and fluffy. This is my favorite mixer!
- Add eggs & vanilla: Mix in 2 eggs and 1 teaspoon vanilla extract. Then add the sour milk.
- Mix dry ingredients: In another bowl, whisk together ⅓ cup cacao powder, 2½ cups all-purpose flour, 1 teaspoon baking soda, and ½ teaspoon salt.
- Combine: Add dry ingredients to wet ingredients, mixing until just combined.
- Stir in zucchini: Gently fold in 2 cups finely grated zucchini (do not drain). I use this grater and it makes it super easy!
- Bake: Pour into a buttered and floured 9×13-inch pan. Sprinkle ½ cup chocolate chips on top. Bake at 350°F for 40–45 minutes, or until a toothpick comes out clean.
- Frost & serve: Cool completely, then top with my Chocolate Buttercream Frosting if desired.
Tips for the Best Zucchini Cake
- Don’t peel the zucchini—once it’s baked, you won’t even notice it.
- Use a fine grater so the zucchini blends seamlessly into the batter.
- Avoid overmixing once the flour is added—this keeps the cake tender.
- For even richer flavor, make the cake a day ahead and let it rest overnight.
- This batter also works beautifully as cupcakes or a two-layer cake.
Variations & Serving Ideas
- Different Frostings: Try cream cheese frosting or even a simple dusting of powdered sugar.
- Add-ins: Walnuts, pecans, or shredded coconut can be folded into the batter.
- Gluten-Free: Use a 1:1 gluten-free all-purpose flour blend.
Storage Tips
- Store covered at room temperature for 2–3 days.
- Refrigerate for up to 5 days.
- To freeze: Wrap unfrosted cake tightly in plastic wrap and foil. Freeze for up to 2 months. Thaw overnight, then frost before serving.
This Moist Chocolate Zucchini Cake is everything you want in a homemade dessert: rich, fudgy, and made with whole, real ingredients. The zucchini keeps it unbelievably moist while the cacao gives it that deep chocolate flavor we all crave. Whether you serve it plain, with a dusting of powdered sugar, or topped with my silky Chocolate Buttercream Frosting, it’s bound to become a family favorite.
If you try this recipe, leave a comment below and let me know how it turned out. And don’t forget to save this recipe on Pinterest so you’ll always have it handy!
Chocolate Zucchini Cake
Bake the best Chocolate Zucchini Cake from scratch with cacao, fresh zucchini, and a rich chocolate buttercream frosting. A moist, decadent dessert made with whole real foods—no boxed mixes here!
Ingredients
- ½ cup whole milk + 1 Tbsp lemon juice (for homemade sour milk)
- 12 Tbsp unsalted butter, softened
- ¼ cup olive oil
- 1¾ cups sugar
- 2 large eggs
- 1 tsp vanilla extract
- ⅓ cup cacao powder
- 2½ cups all-purpose flour (preferably organic, unbleached)
- 1 tsp baking soda
- ½ tsp salt
- 2 cups finely grated zucchini (do not drain)
- ½ cup chocolate chips (for topping)
Instructions
- Make sour milk: Stir 1 tablespoon of lemon juice into ½ cup of whole milk. Set aside for 5 minutes.
- Cream butter, oil, and sugar: In a large mixing bowl, beat together 12 tablespoons butter, ¼ cup olive oil, and 1¾ cups sugar until light and fluffy. This is my favorite mixer!
- Add eggs & vanilla: Mix in 2 eggs and 1 teaspoon vanilla extract. Then add the sour milk.
- Mix dry ingredients: In another bowl, whisk together ⅓ cup cacao powder, 2½ cups all-purpose flour, 1 teaspoon baking soda, and ½ teaspoon salt.
- Combine: Add dry ingredients to wet ingredients, mixing until just combined.
- Stir in zucchini: Gently fold in 2 cups finely grated zucchini (do not drain). This grater makes it super easy!
- Bake: Pour into a buttered and floured 9x13-inch pan. Sprinkle ½ cup chocolate chips on top. Bake at 350°F for 40–45 minutes, or until a toothpick comes out clean.
- Frost & serve: Cool completely, then top with my Chocolate Buttercream Frosting if desired.
Notes
Tips for the Best Zucchini Cake
- Don’t peel the zucchini—once it’s baked, you won’t even notice it.
- Use a fine grater so the zucchini blends seamlessly into the batter.
- Avoid overmixing once the flour is added—this keeps the cake tender.
- For even richer flavor, make the cake a day ahead and let it rest overnight.
- This batter also works beautifully as cupcakes or a two-layer cake.
Storage Tips
- Store covered at room temperature for 2–3 days.
- Refrigerate for up to 5 days.
Nutrition Information:
Yield: 15 Serving Size: 1 pieceAmount Per Serving: Calories: 337Total Fat: 16gSaturated Fat: 8gTrans Fat: 0gUnsaturated Fat: 7gCholesterol: 50mgSodium: 178mgCarbohydrates: 46gFiber: 2gSugar: 28gProtein: 4g
Nutrition facts are calculated automatically and are approximate.
I can’t wait to try this with the zucchini’s from the garden! This looks delicious
Yes! So many zucchini, I hope you love it!
that looks so yummy! we’ve made chocolate zucchini cake before but not like this. definitely have to try this weekend. thanks for sharing!
I really hope you love it!!