Shells,  I don't have an exact recipe, but here goes:  butter 9x12 baking dish, place peeled and sliced apples in dish, sprinkle with "apple pie spice", I use a lot, can't have enough cinnamon.  For the topping, I use 1 cup flour, 1 cup sugar and a stick of butter, mix together to form a crumbly topping and spread on apples.  Bake at about 325 degrees for about 25 mins.   If the apples are very tart, I sprinkle a little sugar on them before adding the topping.  I have used Splenda in place of sugar and this works well.