Chocolate Cake

Preheat oven to 350° and grease 2 (8") round cake pans with cooking spray. Line with parchment. In a medium bowl, whisk coffee and cocoa powder. Let sit 10 minutes. 

In a large bowl, whisk eggs, granulated sugar, oil, butter, and vanilla until combined. Stir in coffee mixture. 

In a medium bowl, whisk flour, baking powder, baking soda, and salt until combined. Add to coffee mixture and mix until just combined. Add sour cream and stir until just combined. Divide batter between prepared pans.

Bake cakes until a tester inserted into the center comes out clean, 25 to 30 minutes. Let cool 15 minutes, then invert onto a wire rack and let cool completely. 

In a small heatproof bowl, microwave chips in 30-second increments, stirring between each, until melted. Let cool to room temperature.

In the large bowl of a stand mixer fitted with the whisk attachment, beat confectioners' sugar, butter, cocoa powder, and salt on medium-high speed until smooth. Add melted chocolate and beat until combined.

Place one cake layer on a platter. Level top, if needed. Frost top of cake. Top with second layer of cake and frost top and sides as desired.