Preheat
oven to 350 degrees F. In mixer bowl, cream together
butter and sugar. Beat in egg.
Combine
flour, baking powder and graham wafer crumbs.
Remove
beaters. Add the dry ingredients, alternately with milk.
Spread
batter in a greased 8 inch square pan. Bake for 30 minutes,
until top of cake springs back when touched lightly.
Cool. Ice with lemon butter icing.