Ingredients

• 2  Cups  all-purpose flour
• 2  Cups  sugar
• 3/4  Cups  unsweetened cocoa powder
• 2  Teaspoons  baking powder
• 1 1/2  Teaspoon  baking soda
• 1  Teaspoon  kosher salt
• 1  Tablespoon  finely ground coffee
• 1  Tablespoon  ground cinnamon
• 1/2  Teaspoon  ground allspice
• 1/2  Teaspoon  ancho chile powder, or to taste
• 1/2  Teaspoon  chipotle chile powder, or to taste
• 1/4  Teaspoon  habañero powder, or to taste
• 1 1/4  Cup  whole milk
• 1/4  Cup  vegetable oil
• 2  large eggs
• 2  Teaspoons  vanilla extract
• 6  Ounces  unsweetened chocolate, chopped
• 1/2  Pound  unsalted butter, cubed, softened
• 1  ripe Hass avocado, halved, pitted, peeled, and cut into chunks
• 1  Teaspoon  vanilla extract
• 1  Cup  confectioners’ sugar, sifted

For the cake:

Preheat the oven to 350 degrees F. Grease two 9-inch round cake pans. Line the bottoms and sides with parchment paper and grease the parchment. Set aside.

Whisk the flour, sugar, cocoa powder, baking powder, baking soda, salt, coffee, cinnamon, allspice, and chile powders together in a medium bowl.

Whisk together the milk, oil, eggs, and vanilla in a large bowl until thoroughly combined. Fold in the flour mixture, mixing until smooth.

Pour the batter into the cake pans and bake for 45 minutes, or until a toothpick or tester inserted in the center of a layer comes out clean. Set on wire racks to cool for 10 minutes, then turn out of the pans onto racks, remove the parchment paper, and cool completely.

For the buttercream:

Melt the chocolate slowly in the top of a double boiler set over medium-low heat. Set aside to cool to room temperature.

With a handheld electric mixer, beat the butter in a medium bowl until fluffy. Beat in the avocado and vanilla. Slowly add the confectioners’ sugar, beating until fully combined. Add the cooled chocolate, mixing until fully incorporated.

Put one cake layer on a serving plate and frost the top. Top with second layer and frost the top and sides of the cake. Refrigerate until ready to serve.

Excerpted from  Hartwood by Eric Werner and Mya Henry (Artisan Books).