Preheat oven to 350°F (175°C) and prepare two greased 9-inch cake pans.
In a bowl, whisk together flour, cocoa powder, sugar, baking powder, baking soda, and salt.
Add eggs, milk, oil, and vanilla, then mix until smooth.
Slowly stir in hot coffee to create a thin batter.
Pour batter into cake pans and bake for 30–35 minutes.
Allow cakes to cool completely on a wire rack.
Beat butter, powdered sugar, cocoa powder, cream, and vanilla until smooth frosting forms.
Frost the cake layers and decorate as desired.