1) Preheat oven to 350 degrees F
2) Place the sliced apples in a 9x13 inch pan. Mix the white sugar, 1 tablespoon flour and ground cinnamon together, and sprinkle over apples. Pour water evenly over all
3) Combine the oats, 1 cup flour, brown sugar, baking powder, baking soda and melted butter together. Crumble evenly over the apple mixture.
4) Bake at 350 degrees F for about 45 minutes