For the cake:
- 2 1/2 cups (10 ounces) whole wheat flour
- 1/2 cup (1 1/2 ounces) unsweetened cocoa powder
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1/2 teaspoon salt
- 1 cup packed light or dark brown sugar
- 1/2 cup granulated sugar
- 1/2 cup (1 stick, 4 ounces) unsalted butter, softened, or vegetable oil
- 1/2 cup buttermilk
- 3 large eggs
- 1 teaspoon pure vanilla extract
- 2 cups (about 1 pound) shredded zucchini (2 small zucchini)
- 1 cup semisweet chocolate chips
For the glaze:
- 1/2 cup heavy cream
- 3/4 cup semisweet chocolate chips
- 2 teaspoons corn syrup
Preheat the oven to 350 degrees F. Lightly grease a 10-cup bundt pan.
In a medium bowl whisk together the flour, cocoa, baking soda, baking powder, and salt. In a large mixing bowl stir together the sugars and butter until smooth. Add buttermilk eggs, and vanilla; mix well. Add half the dry ingredients, stirring until evenly moistened. Stir in the shredded zucchini, then the remaining flour mixture. Stir in chocolate chips. Pour batter into prepared pan.
Bake until the top springs back when lightly touched, about 45 minutes. Remove from the oven and cool on a rack for 15 minutes. Lightly loosen the cake around the edges and center tube by pulling it gently away from the pan with your fingers or running a thin, flexible spatula down the sides, then put the rack on top of the pan and flip the cake over. Remove the pan and allow the cake to cool on rack completely. Once cooled remove cake to a serving platter.
To make the glaze heat the heavy cream to a simmer, and pour over the chocolate chips in a bowl. Stir in the corn syrup, and keep stirring until there are no more lumps and the mixture is smooth. Drizzle over cooled cake on platter.