Preheat oven to 350 deg F.
Mix together 1/4 cup sugar and 1/2 t cinnamon.
Place a layer of apples in greased baking dish, sprinkle with half the sugar-cinnamon mixture, cover with remaining apples and cover with remaining sugar-cinnamon.
Cream 1/2 cup sugar and butter.
Add egg and vanilla and mix well.
Stir in flour and baking powder and spoon over apples, spreading it as best as you can.
Bake 30 minutes.
Best served warm, with vanilla ice cream.