In a mixing bowl, combine the flour, salt, and sugar, then cut in the butter until the mixture resembles coarse crumbs. Gradually add ice water, one tablespoon at a time, until the dough comes together.
Roll out the dough to fit a 9-inch pie pan, and place the bottom crust in the pan. Fill it with the apple mixture, then cover with a second rolled-out crust, sealing the edges.
Cut slits in the top crust for ventilation. Brush the crust with an egg wash made of 1 beaten egg mixed with 1 tablespoon of water for a golden finish.
Bake the pie in the preheated oven for 15 minutes, then reduce the temperature to 350°F (175°C) and bake for an additional 35 to 45 minutes, or until the apples are tender and the crust is golden brown.
Allow the pie to cool for at least 2 hours before slicing to let the filling set. Serve warm or at room temperature, and enjoy your homemade apple pie, a classic treat perfect for any occasion.