Combine brown sugar and cinnamon; cut in butter until crumbly and well mixed. Set aside. Sift together flour, baking powder and salt. Cream shortening in mixer bowl. Gradually beat in sugar. Add egg an vanilla; beat well. Stir in flour mixture by hand alternately with milk, starting and ending with flour mixture. Pour into greased 20 cm square pan. Sprinkle with brown mixture. Bake in 220ºC oven 30 to 35 minutes or until golden brown. Serve warm.