In a large mixing bowl, combine 1 ¼ cups of all-purpose flour, 2 tablespoons of granulated sugar, and ½ teaspoon of kosher salt. Using a food processor, pulse in ½ cup of cold, cubed unsalted butter until the mixture resembles pea-sized crumbs. Gradually add 4-6 tablespoons of cold water, pulsing until a dough forms. Shape the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 1 hour to firm up.

While the dough chills, preheat your oven to 400°F (200°C). Peel and slice about 3 large yellow peaches into ½-inch wedges. In a mixing bowl, toss the peach slices with 2 tablespoons of light brown sugar, a pinch of salt, 1 tablespoon of cornstarch, and ½ teaspoon of cinnamon until well coated. Set the filling aside to let the juices meld together while you roll out the dough.

On a floured surface, roll out the chilled dough into a 12-inch circle about 1/8 inch thick. Transfer the crust to a parchment-lined baking sheet, gently pressing it into place. Brush the surface of the dough with the beaten egg white for a golden finish. Pile the peach filling in the center in concentric circles, leaving a 1-1.5 inch border around the edges.

Carefully fold the edges of the dough over the filling, pleating as you go to create a rustic look. Brush the dough generously with the egg wash made from 1 egg mixed with 1 tablespoon of milk, ensuring a beautiful golden crust. For an extra touch, sprinkle the top with 1 tablespoon of turbinado sugar.

Place the assembled Peach Crostata in the preheated oven. Bake for 30-35 minutes, or until the crust is golden brown and the peach juices are bubbling. Let it cool on a wire rack for at least 2 hours before serving.

After cooling, your Peach Crostata is ready to slice and serve! Enhance with whipped cream or vanilla ice cream.