Preheat oven to 350°F (175°C) and grease two 9-inch round cake pans with butter and cocoa powder.
In a large mixing bowl, sift together flour, sugar, cocoa, baking powder, baking soda, and salt.
Add eggs, milk, oil, and vanilla extract to the dry ingredients and beat on medium speed for approximately 2 minutes until well combined.
Slowly pour in the hot coffee while whisking by hand until the batter is smooth; note that the batter will be very thin.
Divide the batter equally between the two prepared cake pans.
Bake for 30 to 35 minutes or until a cake tester inserted into the center emerges clean.
Cool the cakes in their pans for 10 minutes before inverting onto a wire rack to cool completely before frosting.