Preheat oven to 350 F
Slice apples thinly, then combine with other filling ingredients in bowl. Spread evenly across 8 or 9 inch casserole or baking dish, or similar.
Mix dry ingredients in bowl thoroughly, then add melted butter/margarine. Mix until combined fully.
Bake for 30 to 40 minutes, until golden brown. Let cool 10 minutes and serve.