Preheat oven to 400 degrees F.

On a lightly floured surface, roll one half of the dough into a ⅛ inch thick circle large enough to fit into the bottom of a 9 inch pie plate. Transfer to the pie plate. Refrigerate while you prepare the filling.

In a large bowl, mix sugar, flour and cinnamon. Stir in the peaches and lemon juice.

Add the filling to the chilled pie crust and place back into the refrigerator to chill.

Roll out the remaining dough into a ⅛ inch thick circle. Transfer to the top of the chilled pie.
Trim the edges of the top crust and the bottom crust, leaving enough bottom crust to cover the edge of the top crust neatly. Crimp the dough to seal the edges.

Slash vents in a few places using a sharp knife.

Chill the assembled pie in the refrigerator for at least 30 minutes.

Place the oven rack in the bottom third of the oven. Line a baking sheet with parchment paper or aluminum foil to catch any pie leakage.

Whisk together the egg and tablespoon of milk.

Remove the chilled pie from the refrigerator and brush the top with the egg-milk mixture. Sprinkle with white sugar then place the pie on the prepared baking sheet.

Bake the pie in the bottom third of the oven for about 45 minutes to an hour or until the filling is bubbling in the center.

Serve warm or let cool before serving.