Make the Pie Crust:

1. Prepare the dough: In a large mixing bowl, whisk together flour, sugar, and salt. Add the cold cubed butter and use a pastry cutter or fork to cut the butter into the flour mixture until it resembles coarse crumbs with pea-sized butter pieces remaining. This creates those essential flaky layers.
2. Add water gradually: Drizzle in ice water 1 tablespoon at a time, tossing with a fork after each addition. Add just enough water until the dough begins to come together when pressed. It should be slightly shaggy but hold together—don’t overmix or add too much water.
3. Form and chill: Turn dough out onto a clean surface and gently gather it into a ball. Divide in half, shape each half into a flat disk, wrap tightly in plastic wrap, and refrigerate for at least 2 hours or overnight. This chilling step is crucial for a flaky crust.

Prepare the Filling:

4. Prep the peaches: To peel peaches easily, score an X on the bottom of each peach, blanch in boiling water for 30-60 seconds, then plunge into ice water. The skins will slip right off! Slice peaches into ¼-inch thick wedges, discarding the pits.
5. Mix the filling: In a large bowl, combine sliced peaches, granulated sugar, brown sugar, cornstarch, lemon juice, cinnamon, nutmeg, and vanilla extract. Toss gently until peaches are evenly coated. Let sit for 10-15 minutes to allow the juices to release slightly.

Assemble the Pie:

6. Roll bottom crust: Preheat oven to 400°F (200°C). On a lightly floured surface, roll out one disk of chilled dough into a 12-inch circle about ⅛-inch thick. Carefully transfer to a 9-inch pie dish, pressing gently into the bottom and sides. Trim excess dough, leaving a 1-inch overhang.
7. Add filling: Pour the peach filling into the prepared crust, spreading evenly. Dot the top with small pieces of butter.
8. Create top crust: Roll out the second disk of dough. You can either place it whole over the filling and cut vents, or cut it into ¾-inch strips to create a lattice pattern. For a lattice, weave strips over and under each other in a basket-weave pattern.
9. Seal edges: Trim the top crust or lattice strips, leaving a slight overhang. Fold the overhang under itself and crimp or flute the edges decoratively to seal.
10. Apply egg wash: Brush the top crust and edges with beaten egg, then sprinkle generously with coarse sugar for a beautiful, sparkly finish.

Bake the Pie:

11. Protect and bake: Place pie on a baking sheet to catch drips. Cover the crimped edges with aluminum foil or a pie crust shield to prevent over-browning. Bake at 400°F for 25 minutes.
12. Continue baking: Reduce temperature to 350°F (175°C), remove the foil from edges, and continue baking for 30-35 minutes more until the crust is deep golden brown and the filling is bubbling vigorously through the vents or lattice.
13. Cool completely: Remove from oven and let cool on a wire rack for at least 4 hours before slicing. This cooling time allows the filling to set properly. I know it’s hard to wait, but trust me—it’s worth it!