Cake:
- 1 1/2 cups all-purpose flour
- 3/4 cup unsweetened cocoa powder
- 1 1/2 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 1 cup (2 sticks) unsalted butter, softened
- 1 1/2 cups granulated sugar
- 3 large eggs
- 1 teaspoon vanilla extract
- 1 cup buttermilk
Butternut topping:
- 1 cup unsweetened shredded coconut
- 1/4 cup chopped walnuts
- 1/4 cup packed light brown sugar
- 2 tablespoons unsalted butter, melted
- 1/4 teaspoon ground cinnamon
- 1/8 teaspoon ground nutmeg
Chocolate glaze:
- 1 cup powdered sugar
- 1/3 cup unsweetened cocoa powder
- 3 tablespoons milk
- 1 teaspoon vanilla extract