Preheat the oven to 375°F (190°C).
In a large bowl, whisk together the flour, salt, and baking powder.
2 cup all-purpose flour, 1 teaspoon kosher salt, ½ teaspoon baking powder
Using your hands, a pastry cutter, or a bench scraper, cut the butter into the flour mixture until it resembles coarse crumbs with some pea-sized pieces remaining.
12 tablespoon cold unsalted butter
Add the ice water, one tablespoon at a time, mixing gently until the dough just comes together.
4-6 tablespoon ice water
Form the dough into a disk, wrap tightly, and refrigerate for at least one hour.
Roll the dough into an 11-inch (28 centimeter) circle and fit it into a nine-inch (23 centimeter) metal pie plate.
Gently lift and press the dough into the corners of the plate. Fold excess dough underneath itself and crimp the edges.
Freeze the shaped crust for at least one hour.
Line the crust with parchment paper, and fill it with pie weights.
Bake for 18-20 minutes, until the crust is set but not browned.
Meanwhile, whisk together the egg and water to make the egg wash.
1 large egg, 1 tablespoon water
Remove the parchment and pie weights.
Brush the crust evenly with the egg wash.
Return the crust to the oven and bake for 12-15 minutes more, until golden brown and fully baked.
Set aside and keep warm while preparing the filling.