Prepare the Crust:
In a large bowl, mix flour, salt, and sugar. Cut in the cold butter using a pastry cutter or fork until the mixture resembles coarse crumbs.
Gradually add ice water, one tablespoon at a time, until the dough holds together.
Divide into two discs, wrap in plastic wrap, and refrigerate for at least 30 minutes.
Make the Filling:
In a separate bowl, combine sliced peaches, granulated sugar, brown sugar, cornstarch, lemon juice, cinnamon, vanilla, and salt.
Stir gently to coat and let rest 10 minutes to release juices.
Assemble the Pie:
Roll out one dough disc and place it into your pie dish.
Pour the peach filling evenly into the crust.
If desired, dot with butter pats.
Roll out the second disc and cover the pie (solid top or lattice).
Seal and crimp edges, then cut small slits for steam if using a solid top.
Bake:
Preheat oven to 400°F (200°C).
Brush the top crust with an egg wash (1 beaten egg + 1 tablespoon milk) and sprinkle with sugar.
Bake for 45–50 minutes, or until golden and bubbling.
Let cool for at least 2 hours before slicing to allow the filling to set.