Chocolate Zucchini Sheet Cake
Prep time
Cook time
Total time
A simple and decedent dessert your whole family will love and even if they spot the tiny specs of zucchini they won't care because it so good!
Recipe type: Dessert
Serves: 24-28
  • CAKE:
  • ½ cup butter
  • 4 tbsp cocoa
  • 2 cups white sugar
  • 2 eggs
  • ½ tbsp vanilla
  • ½ cup buttermilk or sour milk (1/2 tsp lemon juice in ½ cup milk and let it set for 5 minutes before adding)
  • 2 cups grated zucchini
  • 2 cups all-purpose flour
  • 1 tsp baking soda
  • ½ tsp salt
  • ½ cup butter
  • 4 tbsp cocoa
  • 3 cups powdered sugar
  • 2-4 tbsp milk
  • 1 tsp vanilla
  2. Preheat oven to 350 degrees. Spray a large 13x18 baking sheet with cooking spray and set aside.
  3. Combine the butter and cocoa in a microwave safe dish and microwave on high for 60-90 seconds or until the butter is melted and hot and can dissolve and activate the the cocoa (it will look nice and dark, kind of like runny melted chocolate)
  4. While the butter and cocoa are in the microwave measure the sugar out into a large mixing bowl.
  5. Stir the hot butter cocoa mixture into the sugar (this helps cool the butter chocolate mixture down before you add the eggs)
  6. Add the eggs and vanilla, whisk well or you can use a hand mixer to mix it.
  7. Add in the butter milk and again whisk or use you hand mixer to thoroughly combine it.
  8. Next, mix in the zucchini
  9. Lastly, Add the flour, baking soda and salt, mix until well combined.
  10. Pour batter into the prepared 13x18 baking dish and bake at 350 degrees for 18-20 minutes or until a toothpick inserted in the center comes out clean.
  11. Once the cake is baked you have to choices. You can frost it immediately or you can wait for it to cool. I like to wait until it is mostly cooled.
  13. In a small sauce pan combine the butter, cocoa and two tbsp of milk. Bring to a boil. Stir well.
  14. Remove from heat and whisk in 3 cups of powdered sugar, 1 tsp vanilla and an additional tbsp of milk of two if needed for consistency. You can use your hand mixer instead of a whisk if you want to.
  15. The frosting should be nice and smooth, pour it onto the cake and spread evenly.
  16. Enjoy!
  17. This cake can be covered and stored at room temperature for 3-4 days. You can also keep it in the fridge if you prefer.
Recipe by Real Life Dinner at