Go Back
+ servings
Overhead picture of a chocolate zucchini loaf cake cut into slices.

Chocolate Zucchini Loaf Cake With Fudgy Chocolate Icing

Audrey
Chocolate Zucchini Loaf Cake with Chocolate Icing is rich, moist, and deeply chocolatey, thanks to grated zucchini that keeps it soft. Finished with a sweet, glossy chocolate icing, it’s the perfect simple dessert or snack.
Prep Time 30 minutes
Cook Time 50 minutes
Total Time 1 hour 20 minutes
Course Dessert
Cuisine American
Servings 10 slices
Calories 555 kcal

Equipment

  • 8x4-inch loaf pan
  • Parchment Paper
  • Mixing bowls (medium and large)
  • Whisk
  • Spatula or wooden spoon
  • Measuring cups and spoons (or a kitchen scale for accuracy)
  • Grater (for zucchini)
  • Wire rack (for cooling)
  • Toothpick or cake tester
  • Small offset spatula or spoon (for spreading icing)

Ingredients
  

For the cake:

  • 210 g all-purpose flour 1 ¾ cups
  • 45 g unsweetened cocoa powder ½ cup
  • 1 teaspoon baking soda
  • ½ teaspoon baking powder
  • ½ teaspoon kosher salt
  • 1 teaspoon espresso powder optional, enhances chocolate flavor
  • 200 g brown sugar 1 cup, packed
  • 120 ml neutral oil ½ cup
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 120 ml whole milk or buttermilk ½ cup
  • 260 g grated zucchini about 2 cups, loosely packed
  • 85 g mini chocolate chips ½ cup, optional

For the chocolate icing:

  • 90 g unsalted butter ¼ cup or ½ stick
  • 40 g unsweetened cocoa powder ½ cup
  • 360 g powdered sugar 3 cups
  • 6 tablespoon boiling water
  • 2 teaspoon vanilla extract

Instructions
 

  • Prep the pan: Preheat oven to 350°F (175°C). Grease and line an 8x4-inch loaf pan with parchment paper.
  • Mix the dry ingredients: In a medium bowl, whisk together the flour, cocoa powder, baking soda, baking powder, salt, and espresso powder.
  • Make the batter: In a large bowl, whisk together the brown sugar, oil, eggs, vanilla, and milk until smooth and emulsified.
  • Fold in zucchini: Stir in the grated zucchini and chocolate chips (if using) until evenly distributed.
  • Combine & bake: Add the dry ingredients to the wet and fold gently until just combined. Pour the batter into the prepared pan and smooth the top. Bake for 45–55 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs.
  • Cool the cake: Let the loaf cool in the pan for 10–15 minutes, then transfer to a wire rack to cool completely.
  • Make the chocolate icing: In a medium bowl, whisk together the boiling water and cocoa powder until smooth. Add the softened butter and vanilla, then beat in the powdered sugar gradually until smooth and glossy. The icing should be thick but pourable—add a splash more water if needed.
  • Ice the cake: Once the cake is fully cool, spread the icing generously over the top and let it set for 15–20 minutes before slicing.

Nutrition

Calories: 555kcalCarbohydrates: 84gProtein: 6gFat: 15gSaturated Fat: 9gPolyunsaturated Fat: 6gMonounsaturated Fat: 7gTrans Fat: 0.3gCholesterol: 61mgSodium: 267mgPotassium: 187mgFiber: 4gSugar: 61gVitamin A: 244IUVitamin C: 0.1mgCalcium: 55mgIron: 2mg
Keyword chocolate
Tried this recipe?Let us know how it was!