01 -
Preheat the oven to 350°F (175°C). Lightly spray two 8 or 9-inch round cake pans with cooking spray and line them with parchment paper.
02 -
Sift flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt into a mixing bowl. Whisk until well combined.
03 -
In a large mixing bowl, whisk instant espresso powder and hot water. Add buttermilk, vegetable oil, eggs, and vanilla. Mix until well blended.
04 -
Gradually add dry ingredients to the wet mixture. Stir until all the flour is incorporated and the batter is smooth.
05 -
Distribute the batter evenly between the prepared cake pans. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Cool the cakes completely at room temperature.
06 -
Using a stand mixer or hand mixer, whip unsalted butter and vanilla extract until light and fluffy. Gradually sift in icing sugar and cocoa powder. Beat on low speed initially, then increase to medium-high. Add milk, one tablespoon at a time, until desired consistency is achieved.
07 -
Place chocolate chips in a small bowl. Heat whipping cream in a saucepan until it begins to bubble around the edges. Remove from heat and pour over the chocolate chips. Let rest for 1 minute, then whisk until smooth.
08 -
Cool cakes completely before assembly. Level the tops of the cakes with a knife, then layer with buttercream. Optionally, slice each cake into two layers for a total of four layers. Spread buttercream between each layer and coat the entire cake with a smooth buttercream covering.
09 -
Slightly warm ganache if thickened. Pour ganache over the top of the cake, allowing it to drip over the edges. Use a piping bag to decorate with extra buttercream and chocolate chips if desired.