Instructions

1. Make the crust: Mix the vinegar with ½ cup ice water; transfer to the freezer. In a large bowl, whisk together the flour, sugar, and salt. Add the cold butter and use your fingertips to incorporate, squeezing the pieces and gently tossing the mixture until a dough comes together in chunky, pea-size pieces with some larger pieces remaining. Retrieve the vinegar mixture from the freezer and pour half around the edge of the bowl. Use a fork to incorporate, gently tossing the dough. Add almost all of the remaining vinegar mixture and continue tossing, just until the dough becomes slightly shaggy but not overly moist. If the dough is too dry, drizzle in the remaining vinegar mixture and continue tossing, just until the dough keeps its shape and holds together in a solid mass when squeezed. Turn the dough out onto a clean work surface, divide it in half, then gently press each half into an even ½-inch disk. Wrap each disk tightly in plastic and refrigerate for at least 1 hour and up to 3 days.
2. Line a large rimmed baking sheet with parchment paper and set aside. Lightly flour a sheet of parchment and a rolling pin. Retrieve 1 disk of dough, unwrap, and place it on the parchment. Lightly flour the surface of the dough, then roll it out to an even 13-inch circle, about ⅛ inch thick. Lightly flour the rolling pin once more, then place it on the far left edge of the circle and carefully roll the dough around the pin, gently lifting it away from the parchment in one smooth sheet. Place the dough-wrapped rolling pin over the far right edge of a 9-inch pie plate and unroll the dough, centering it over the pie plate. Use your fingers to ease (not stretch) the dough along the bottom and the sides of the pie plate. Trim to a 1-inch overhang. Transfer to the prepared baking sheet, cover loosely with plastic wrap, and refrigerate.
3. Lightly flour the same sheet of parchment and the rolling pin. Retrieve the remaining disk of dough, unwrap, and place it on the parchment. Lightly flour the surface of the dough, then roll it out to an even 12-inch circle, about ⅛ inch thick. To make a double-crust pie, slide the dough (still on the parchment) onto a second baking sheet, cover with plastic wrap, and refrigerate while you make the filling. (Alternatively, make a lattice: using a pastry cutter or a paring knife, cut the circle into ten 1-inch strips. Slide the strips (still on the parchment) onto a baking sheet, cover with plastic wrap, and refrigerate.)
4. Place 1 rack at the bottom of the oven and another rack in the center; preheat to 425°F.
5. Make the filling: In a large bowl, add the peaches and lemon juice, then using your hands or a bowl scraper, gently toss to combine. In a medium bowl, whisk together both sugars, the cornstarch, cinnamon or ginger, and salt. Retrieve the pie shell and top crust (or lattice). Add the sugar mixture to the peaches, then using your hands or a bowl scraper, gently fold to combine. Transfer the peaches to the pie shell, leaving any accumulated juices behind in the bowl; set the juices aside. Sprinkle the raspberries over the peaches, then dot the fruit with the butter.
6. Using a pastry brush or your index finger, moisten the edge of the bottom crust with a bit of the reserved peach juices. Place your top crust (or lattice) over the filling and trim to a 1-inch overhang. Gently press the edges to seal, tucking the overhang of the top crust underneath the overhang of the bottom crust, then crimp with your fingers or the tines of a fork. Beat together the egg yolk and milk; brush the top of the pie (not the edges) with the egg wash and sprinkle evenly with sanding sugar. Using a paring knife, cut 4 slits in the center to vent. Freeze until the crust is very firm all over, at least 15 minutes and up to overnight.
7. Retrieve the pie, place back on the parchment-lined baking sheet, and bake on the bottom rack until the top crust is lightly golden, 20–25 minutes. Lower the temperature to 375°F, transfer the pie to the center rack, and continue baking until the top and bottom crusts are deeply golden and the juices are thickened and bubbly, about 1 hour 15 minutes more (if the edges or top begin to brown before the filling is thickened and the bottom crust is cooked, tent with foil). Transfer to a wire rack and let cool for at least 2 hours before cutting. Any leftovers can be stored, wrapped tightly in plastic, at cool room temperature for up to 3 days.