In a medium bowl, combine butter, sugar, egg and flour. Stir with spoon for a few moments until mixture hangs together a bit. Then use hands to form dough. Pat a bit more than ½ of the dough on the bottom and sides of 9 inch pie dish.
Fill pie shell with apples and dust them with cinnamon. Crumble the rest of the dough over top of apples until they are more or less covered evenly. If desired, sprinkle a handful of sugar over the top for a sugary top crust. Bake in preheated oven for 45 minutes.