Make the pie dough:

1. In a stand mixer fitted with a flat beater attachment, combine the flour, salt, and sugar with your fingertips. Add the cold butter and mix until the dough looks like coarse sand. Turn the machine off and blend any large pieces of butter with your fingertips, making sure there are no pieces of butter larger than the size of a pea.
2. In a measuring cup, combine the bourbon and ice water. With the stand mixer on low speed, slowly dribble in the bourbon water one tablespoon at a time. Add just enough liquid for the dough to pull away from the sides of the bowl. (You may not need to use all of the bourbon water for the dough.) Pinch the dough between your fingertips ; it should be smooth, not sticky or crumbly. Gently press the dough together. Divide in half and gently shape each half into a flat disk. Wrap each disk in plastic wrap and refrigerate for at least 30 minutes and up to 3 days.

Make the filling:

1. In a large bowl, combine the sugar, lemon zest, cinnamon and vanilla seeds and rub between your fingers to combine (this infuses the sugar). Add the peaches, sea salt, and cornstarch. Toss until the peaches are evenly coated.

Assemble and bake the pie:

1. On a lightly floured surface, roll out one piece of dough, rotating in quarter-turns, until 12-14” in diameter and 1/8” thick. Gently fit the dough into a 9” pie plate. Trim the edges of the dough with scissors, making sure to leave at least a 1” overhang.
2. Crack the egg into a small dish. Without breaking the yolk, use a pastry brush to gently coat the sides and bottom of the pie shell with a thin layer of egg white (reserve the remaining egg for brushing the top of the pie). Place in the fridge for 30 minutes.
3. Meanwhile, roll out the remaining disk of dough, rotating in quarter-turns until 1/8” thickness. Cut the dough into six 1-1/2” wide strips. Place the strips on a baking sheet in the refrigerator until ready to use.
4. Tumble the peaches into the chilled pie shell. Scatter the butter over the peaches. Place three strips of dough on top of the peaches horizontally. Then, one by one, place the remaining strips vertically, lifting every other horizontal strip to create a basket weave lattice. Trim the edges with scissors even with the bottom crust. Gently press to seal the edges of the pie dough so the top and bottom crusts seal together, then carefully roll the crust over itself so that the rolled edge sits on the lip of the pie plate. Crimp the edges. Beat the reserved egg and gently brush onto the edges and top of the pie. Sprinkle the top with sugar. Place the pie in the fridge for 20 minutes to set the pastry.
5. Preheat the oven to 425 degrees. Line a rimmed baking sheet with a piece of foil.
6. Place the pie on the lined baking sheet and bake in the oven for 20 minutes. Reduce the oven temperature to 375 degrees and bake until the crust is golden brown, about 30 minutes. Cover the edges of the crust with foil if it is browning too quickly. Let cool on a wire rack for an hour if you can wait. Leftovers will keep at room temperature for 2 days or in the fridge for 3 days.