Spread apples and sauce in an even layer onto pie crust. If you choose to make a lattice pie, this is how you do it
. Otherwise, place the other crust (the one you put on the baking sheet) over the apples. Tuck any excess overhang pastry under the bottom crust, then crimp the edges using your fingers or a fork. Make 4 slits in the center to let steam escape while baking. Brush the crust with egg (a very thin coating), then sprinkle with sugar if you like.