In a large bowl, toss everything, EXCEPT butter, together to break down sugar and equally distribute contents.
Rub the cubed/grated butter into flour mixture using both hands until none of the dry mix is visible.
Chill in freezer for about 10-15 minutes. This hardens it to make it easier to crumble on top.
Break up topping as you distribute it evennly over the apples.
Place pan on baking sheet to catch any drippings. Bake on a middle oven rack at 375°F for about 30-35 minutes. Apples should be bubbling and top golden.