2 1/2 cups all-purpose flour
1/2 teaspoon kosher salt
16 tablespoons unsalted butter, cold and cut into pieces
4 to 10 tablespoons ice water
6 apples (about 3 pounds), peeled, cored, and thinly sliced
3/4 cup light brown sugar
3 tablespoons all-purpose flour
2 teaspoons ground cinnamon
2 teaspoons freshly grated nutmeg
2 teaspoons vanilla extract
1 teaspoon ground ginger
Pinch kosher salt
2 tablespoons unsalted butter, chilled and cut into pieces
Milk, for brushing
Cinnamon sugar, for sprinkling