Prepare your cake pans by lining them with wax paper. Or, if you prefer, grease and flour your pans. Preheat your oven to 350° F.
Separate the eggs. Set the yolks aside and beat the whites until they are stiff. Pour the whites into a bowl for later.
Cream the butter. Add the sugar, and cream again.
Add the egg yolks and mix well.
Add the coffee, vanilla, flour, and baking powder. Mix until combined and then beat for 2 minutes.
Stir in the stiffly beaten egg whites. Be gentle, you don't want to undo all your hard work.
Pour the mixture into the prepared cake pans. Bake for 25-30 minutes in a 350° oven. Test for doneness by pressing the top center of the cake. If a finger indentation pops back up and disappears, the cake is done. If the indentation stays, it probably needs another ten minutes or so.
Let the cake cool before icing.