Use this recipe when making our Mint Chocolate Cake.
Preheat oven to at 350 degrees. Coat cake pans with cooking spray; cover bottoms with parchment, and coat again. Set aside. Whisk cocoa powder into coffee in a large bowl until cocoa has dissolved; set aside.
Sift together flour, baking soda, and baking powder in a large bowl; set aside.
Put butter and sugar into the bowl of an electric mixer fitted with the paddle attachment; mix on medium-high speed until pale and fluffy. Add eggs, 1 at a time, mixing well after each addition. Mix in half of the flour mixture. Mix in coffee mixture. Mix in remaining flour mixture. Divide batter among prepared pans.
Bake until a cake tester inserted into centers comes out clean. Transfer to wire racks; let cool in pans slightly. Invert cakes onto racks. Remove parchment; reinvert. Cakes can be wrapped in plastic and stored at room temperature up to 1 day.
To assemble: Cut each cake horizontally into three 1-inch layers. Brush each layer with syrup. Spread ganache over 1 layer; top with another layer. Spread with dark-coffee buttercream. Top with remaining layer; spread with vanilla buttercream. Frost tier with buttercream.