Preheat oven to 425.
Peel apples and slice thin in a large mixing bowl. Set aside.
Press one of the pie crusts into a 9-inch pie plate.
To the apples, add both sugars, flour, cinnamon, and salt.
Place the mixture in the pie plate and dot with the butter that has been sliced thin.
Cover with second pie crust, pinching the two crusts together.
Separate an egg, and using the egg white, brush over the top of the crust.
Make 3-4 slits in the top of the pie. Sprinkle with granulated sugar.
Bake for 40-45 minutes until the juice begins to bubble through the slits.
Serve warm with ice cream.