Preheat the oven to 350°F (175°C) and grease two 9-inch round cake pans.
In a large bowl, sift together flour, cocoa powder, baking powder, baking soda, and salt.
In another bowl, beat sugar, brown sugar, eggs, and oil until smooth.
Gradually add the dry ingredients to the wet ingredients, alternating with coffee and milk.
Pour the batter into the prepared pans and bake for 25-30 minutes. Let cool completely.