After the filling has cooled down, preheat oven to 400 degrees F.
Cut remaining 1 tablespoon of cold butter into small cubes. Set aside.
Get a 9-inch round pie pan ready. Roll out the dough to a 12-inch circle using a rolling pin on a floured surface to about ¼ inch thick. Repeat for the second disk.
Transfer dough to a 9-inch pie pan. Fill with the cooled apple pie filling and dot with the remaining 1 tablespoon butter cut into small cubes. Cover the pie with the second rolled out dough. Trim any overhang or excess dough. Seal edges with a fork or with your fingers. Make a few slits at the top to let the steam escape. Alternatively, you can make a lattice pattern. For instructions, see the “How to Make a Lattice Pie Crust” above.
If you made a lattice top, refrigerate the pie for about 15-20 minutes. If you did not, skip this step.
Make the egg wash by whisking the egg with heavy cream or milk. Brush the pie dough with egg wash and sprinkle with coarse sugar if desired.
Place pie on a large baking sheet and bake for 25 minutes at 400 degrees F. Remove pie from oven and put a pie crust shield or cover edges with foil. Lower oven temperature to 375 F and bake for an additional 30-35 minutes until golden brown and bubbly.
Let it cool on a wire rack for 3 hours before serving. Trust me, if you cut into it before it has cooled down, it will fall apart (been there, done that). Enjoy!