~-----TOPPING: Cream sugar and butter until soft and smooth. Sift together flour, baking powder, and salt. Add sifted ingredients alternately with milk. Fold in egg whites beaten stiff. Pour into large baking pan. Mix topping together until it forms pea-sized crumbs. Blend in pecans. Spread over the top of batter and bake at 180ºC for 40-50 minutes. Cut into squares.