Preheat oven to 350°F. Grease and line three 8-inch cake pans.
Mix dry ingredients: flour, sugar, cocoa, baking soda, baking powder, salt.
Whisk wet ingredients separately: eggs, milk, oil, vanilla.
Combine wet and dry ingredients until just mixed.
Add hot coffee and water, mix until smooth.
Divide between pans, bake 25-30 minutes.
Cool 10 minutes in pans, then completely on racks.