Peel and slice apples. Grease an oblong deep glass baking dish (3" high). In a bowl, use a fork to mix flour, sugar, baking powder, salt, and the egg - mix until you have a crumb mixture. Layer the apples in the glass baking dish and pour the crumb mixture evenly over the apples. Pour melted margarine evenly over the top of the crumbs. Sprinkle entire top with cinnamon. Bake at 350 degrees for 30-40 minutes. Test with a fork for doneness - apples should be soft.