For the filling, Mix together dry ingredients in a large bowl. Peel, core, and slice apples, toss with the dry ingredients until evenly coated, and sugar mixture is moistened from apples.
Pack apple mixture evenly into our pie shell. The apples will be piled high, but will cook down some in the oven. Finish with crumb topping.
For the crumb topping, Combine dry ingredients in a bowl. You can cut in butter with a fork or a pastry blender.
Mix until butter is worked into the dry ingredients, it should look lumpy but dry. Smooth the crumb mixture over the apples.
Preheat oven to 375°F.
Place pie on a sheet pan and bake for about an hour (maybe a little longer). You will know the pie is done when juices bubbling out of it look thick, or a paring knife is easily inserted in the center and the apples are tender. The pie will sink down as it cools.