Peach Galette

Preheat oven to 350 degrees F. Pulse all-purpose flour, pastry flour, salt and 2 tablespoons sugar in a food processor until combined, 3 to 4 pulses. Add butter; pulse until the mixture resembles coarse meal, 8 to 10 pulses. Add vinegar, 4 tablespoons ice water and 1/4 teaspoon vanilla; pulse, adding up to 2 tablespoons more ice water as needed, 1 tablespoon at a time, until the dough begins to clump together. Turn the dough out onto a piece of plastic wrap; gently press into a 4-inch disk. Cover with additional plastic wrap. Carefully roll the dough (between the plastic) into a 12-inch round. Place in the freezer for 5 minutes.

Remove the dough round from freezer; remove and discard the top piece of plastic wrap. Line a baking sheet with parchment paper. Invert the dough onto the prepared baking sheet; remove and discard the remaining plastic wrap.

Combine cornstarch and 4 tablespoons sugar in a large bowl. Add peaches, peach preserves and the remaining 1 teaspoon vanilla; stir to completely coat.

Mound the peach mixture in the center of the dough round, leaving a 3-inch border. Fold the dough edges up and over the peaches, pleating as you go and leaving about a 5-inch-diameter circle of exposed peaches in the center.

Whisk egg white and water in a small bowl; brush over the dough edges. Sprinkle the edges evenly with the remaining 1 teaspoon sugar.

Bake the galette until the crust is golden brown and the filling is bubbly, 55 minutes to 1 hour. Remove the galette from the parchment paper and transfer to a wire rack. Let cool for at least 30 minutes and up to 1 hour before slicing and serving.