At this point, pre-heat your oven to 375° F.
Sprinkle a clean surface with part of the extra flour, so the dough won't stick to the surface. Separate the dough into 2 halves, set one half aside, and roll out the other half of the dough with a rolling pin, equally rolling in all directions, 'til the dough is about 2 to 3 inches bigger around than your pie plate.
Fold the crust in quarters; then carefully place the dough in the pie plate, unfolding it to cover the entire plate.
Smooth it out inside the pie plate, and then trim off any overhanging edges with kitchen shears or a knife; leave enough dough (about 1/2 inch overlapping) so you can flute the edges of the crust.
Pour the apple pie filling into the unbaked pie shell.
Sprinkle the floured surface with more of the extra flour. Then roll out the other half of the dough with your rolling pin, 'til the dough is 2-3 inches bigger than the pie plate, allowing extra room for the filling.
Fold this top crust in quarters, and carefully place over the filling and bottom crust, unfolding this top crust to cover the entire pie.
Trim off any overhanging edges, leaving about 1/2 inch overlapping.