Preheat oven to 400°F.
Combine the sugar, flour, and cinnamon in a large bowl until well-mixed.
Add the apples, tossing until well coated.
Line a pie pan with one of the pie crusts.
Pour the sugar-coated apples into the pie pan.
Dot with cubes of butter.
Place the second crust on top of apples and butter and seal.
Cut a few slits for steam to escape on top layer of crust.
Spread a small amount of milk on top of the pastry and sprinkle with leftover sugar.
Bake for 50 minutes, placing a cookie sheet on a lower rack to catch overflow.
Let pie cool, then slice and serve.