Make the dough: Mix flour and salt, cut in cold butter until crumbly, then add ice water to form a shaggy dough.
Shape and chill: Divide the dough into two discs, wrap in plastic, and chill for at least 2 hours.
Roll bottom crust: Roll out one dough disc, line a pie dish, and trim the edges.
Prepare filling: Toss apples, cherries, brown sugar, cornstarch, cinnamon, and vanilla in a bowl.
Assemble pie: Add filling to the crust and roll out the second disc for a lattice top or braided crust.
Finish crust: Arrange the lattice or braids, trim and crimp edges, and brush with egg wash.
Bake: Bake at 425°F for 15 minutes, then reduce to 350°F and bake 50-55 minutes until golden and bubbly.
Cool and serve: Let cool for 1-2 hours before slicing. Enjoy with ice cream!