Topping: Melt butter, and combine with sugar and cinnamon. Set aside.
Base: In large bowl combine flour, baking powder, salt and white sugar. Mix well. Cut in butter and add egg and milk. Mix quickly with fork till moistened. Put in greased 8 x 8 pan and cover with topping.
Bake at 350°F for 35 minutes or till knife comes out clean when tested. Serve hot with extra butter spread on top of cake.