White the egg whites until they are light and fluffy, forming soft peaks, then set aside.
Cream the butter and sugar, then add the flour, vanilla, baking powder, and salt and mix untillcombined.
Fold in the egg whites, until they are fully incoorperated.
Pour into two round cake pans, or one 9x13 pan. Bake at 350 for 25-30 minutues or until a knife comes out clean.
Allow the cake to cool fully before frosting