Put flour, sugar, and baking powder in a bowl.
Beat one egg by hand and add to the flour mixture. Beat well by hand.
Grease an 8 x 8 baking dish with butter or margarine. Skin, core, and slice apples thinly and place in bottom of dish until bottom is covered. Sprinkle with 1 tsp. cinnamon and 2 TBSP white sugar. Pour flour mixture over the top. Cut little pieces of butter and "dot" the top of the mixture with butter. Sprinkle 2 TBSP of water over the top of the mixture.
Bake at 350 degrees until top is crisp and apples are done (about 40-45 minutes). To test apples for doneness, put a toothpick down through the mixture. If the toothpick comes out clean and the apples feel soft, it's done. If not, bake a few more minutes and retest.