Prepare the Homemade Pie Crust or All Butter Pie Crust through step 5. Divide the chilled dough into two workable discs, one for the bottom crust and one for the top.
Combine the chopped peaches, granulated sugar, flour or instant tapioca, lemon juice, optional ginger, and cinnamon in a large bowl. Place the filling in the refrigerator while you work with the dough so the peaches remain firm.
Position an oven rack in the lower third and heat the oven to 425°F (218°C). Set a baking sheet on the bottom rack to catch any juices that bubble over.
Roll one chilled dough disc on a floured surface into a 12-inch circle, turning it as you roll, then fit it into a 9-inch round pie dish. Press the dough smoothly into the dish, spread in the filling, and scatter the cold butter cubes over the peaches.
Roll the second chilled dough disc into a 12-inch circle and cut it into strips with a pastry wheel, sharp knife, or pizza cutter. Weave the strips over the filling, trim excess dough, fold and seal the edges, then crimp the rim with a fork.
Brush the lattice lightly with the egg wash and add the coarse sugar, if using. The wash should leave the dough lightly coated rather than dripping into the filling.
Bake at 425°F for 20 minutes, then reduce the oven temperature to 375°F (190°C) without removing the pie. Cover the edges with a pie crust shield and continue baking for 45–50 minutes, until thick juices bubble through the center and the filling reaches about 200°F (93°C).
Move the baked pie to a cooling rack and leave it undisturbed for at least 4 hours before cutting. The filling will firm as it cools, giving each slice cleaner edges and a glossy peach center.
Cover leftovers tightly and store in the refrigerator for up to 5 days. Keep the pie chilled once cooled to preserve the pastry and fruit filling.