This chocolate zucchini cake is moist, rich, and topped with a decadent chocolate frosting.
August is zucchini season and I love that there so many ripe fruits and vegetables this time of year. In Minnesota, a lot of our local produce is only ripe in July and August because we have a pretty short growing season.
I love how the addition of zucchini to a cake makes it super moist. And by moist, I mean really moist. (so sorry for using the word moist three times right there.)
This zucchini cake is not just moist, it is incredibly full of chocolate. Cocoa powder, chocolate chips, and a fifties style chocolate frosting. All of these contribute to a rich chocolate cake.
Making the Cake
When you make the cake, you may notice that the batter may seem thick. The batter will thin significantly after you add the zucchini, making it the right consistency for baking.
One thing that can help this cake come out of the pan easier, is lining the pan with parchment paper. I recommend using one long strip of parchment cut to fit the pan vertically with the parchment on the horizontal sides of the cake overhanging over the sides.
This frosting is a classic mid-century chocolate frosting that is made on a stove. Adapted from my great grandmother’s recipe, it is a simple frosting made with granulated sugar, butter, milk, chocolate, and vanilla.
The first step to success is combining the sugar, milk, and butter over a medium-low heat. Once the mixture boils for at 45 seconds all you have to do is add the chocolate and vanilla and stir.
This frosting will get a skin on top if you don’t stir it occasionally while it cools. I would recommend stirring it every 3-5 minutes until it is thick enough to spread on to the cake.
Another frosting option is to use a ganache like in my Dark Chocolate Ganache Cake .
Chocolate Zucchini Cake
Chocolate Zucchini Cake
- 2 cups All Purpose Flour (260g)
- 2 cups Sugar (414g)
- 10 tbsp Unsweetened Cocoa Powder (56g)
- 1 tsp Cinnamon
- 1 tsp Baking Powder
- 1 ¼ tsp Baking Soda
- ½ tsp Salt
- 2 Eggs
- ¾ cup Sour Cream (or Yogurt)
- ¼ cup Vegetable Oil
- 1 tbsp Pure Vanilla Extract
- 2 cups Shredded Zucchini
- 1 ½ cups Chocolate Chips (divided)
- 6 tbsp Butter
- 6 tbsp Milk
- 1½ cups Sugar
- 1 tsp Pure Vanilla Extract
- 1 cup Chocolate Chips
- Preheat your oven to 350˚ Fahrenheit. Line a 9×13 pan with parchment paper and spray liberally with cooking spray.
- In a large bowl combine the flour, cocoa powder, sugar, cinnamon, baking powder, baking soda, and salt.
- In a small bowl combine the eggs, sour cream, oil, and vanilla. Pour over the dry ingredients and stir until just combined. The batter will be very thick.
- Add the zucchini and one cup of the chocolate chips. Spread the batter into the prepared pan. Sprinkle the remaining ½ cup of chocolate chips over the top of the batter.
- Bake the zucchini cake for 35-40 minutes or until a toothpick inserted into the center of the cake comes out clean. Allow the cake to cool.
- In a small saucepan bring the butter, sugar, and milk to a rolling boil over medium heat stirring constantly. Let the mixture boil for 45 seconds and then remove it from the heat.
- Stir in the chocolate chips and the vanilla until smooth and completely melted. Allow the frosting to cool to a spreadable consistency stirring every few minutes so that a skin does not form on the frosting.
- Spread the frosting over the cake. Allow the frosting to set for at least 15 minutes.
- Enjoy! The cake will keep in an airtight container for up to 3 days or in the freeze for up to 3 weeks.