Preheat oven to 400 degrees

Roll crust into pie pan

Combine sugar, cinnamon, and corn starch in a bowl

Add apples to sugar mixture and mix until apples are coated

Spoon apple filling into crust and sprinkle butter chunks on top

Cover with top pie crust and cut slits into the top or do a lattice pattern

Brush with egg wash

Place pie on center rack and bake for 20 minutes

After 20 minutes reduce heat to 350 and cook for another 30 minutes