Preheat oven to 375° F. Peel, core and slice about 4 cups of tart apples. Place them in a buttered casserole or baking dish.
Place topping ingredients together in a bowl. Work with your fingers or a fork until the texture is crumbly, but not oily. Spread on top of the apples. Bake about 30 minutes.
You can substitute 1 cup of apples with fresh cranberries. Add ¼ cup sugar to the fruit.
Footie Lund, based on the Joy of Cooking