Preheat the oven to 350°F (175°C).
In a mixing bowl, combine flour, baking powder, and sugar.
Add butter and eggs; stir until smooth.
Dissolve espresso powder in a small amount of hot water and mix into the batter.
Pour batter evenly into greased cake pans.
Bake for 25–30 minutes, or until a toothpick inserted comes out clean.
Let sponge layers cool completely.
Prepare coffee buttercream (softened butter + powdered sugar + dissolved coffee + milk if needed) and frost the cake.
Dust with cocoa powder for presentation and serve.