In a bowl, combine flour and salt; cut in butter until crumbly. Press onto the bottom and up the sides of a 9-inch pie plate. Arrange apples over crust.
Combine sugar and cinnamon; sprinkle over the apples. Bake at 375°F for 20 minutes.
For custard, whisk milk, egg and sugar until smooth; pour over apples. Bake 25-30 minutes longer or until a knife inserted near the center comes out clean. Cool on a wire rack. Refrigerate leftovers.