Preheat the oven to 375°F. Use a 9- to 10-inch pie pan. Roll half the dough into a disk about two inches larger than the pie pan. Line the pie pan. Refrigerate the pie shell. Roll the remaining dough to the same size and thickness as the first disk. Place on a sheet pan and refrigerate or freeze.
Peel, halve, core, and slice the apples slightly thinner than 1/2 inch. Toss the sliced apples with the 2/3 cup sugar and the flour and put them in the lined pie pan. Be gentle so you don't break up the slices. Dot the apples with the butter. Place the second pastry round over the pie and let thaw slightly.
Trim the edges of the pastry rounds with scissors so each protrudes about 1/2 inch out from the rim. Pinch the edges together and roll up to seal the pie with a rope like border.
Make 6 slits in the top of the pie with a paring knife. Brush the edges and top of the pie with the egg wash. Sprinkle the top of the pie with sugar. Bake for 90 minutes, or until golden brown with bubbling juices coming out of the vents.
Let cool for at least 1 hour before serving.