Peel and core apples, cut into thin slices, cut each slice in half.
Cream butter, add sugar and beat until light and fluffy; beat in egg.
Fold in sifted flour and salt alternately with milk, mix well.
Spread mixture into well-greased 8 inc sandwich tin, arrange a whirl of apple slices on top, sprinkle with combined cinnamon and extra sugar. Bake in moderate oven for around 45 minutes.