Pre head oven to 400
Prepare 1 pie crust in a pie plate and set aside.
Peel, core and slice apples and put them in a large bowl. add, sugar, flour and cinnamon and stir well to coat.
Pour mixture into unbaked crust, dot with butter. Cover with top crust and seal edges. Cut 4 slits in top for steam to escape. Brush with egg and sprinkle with sugar.
Bake for 30 to 40 minutes, until pie is golden brown and apples are tender