In a mixing bowl, combine flour and butter until the mixture resembles coarse crumbs. Gradually add ice water until the dough comes together. Divide the dough in half, wrap in plastic, and refrigerate for at least 30 minutes.
Roll out one half of the dough and fit it into a pie dish. In another bowl, mix sliced nectarines, sugar, cornstarch, lemon juice, and cinnamon. Pour the filling into the pie crust.
Roll out the second half of the dough and place it over the filling. Trim and crimp the edges, and cut a few slits in the top crust to allow steam to escape.
Bake for 45 minutes or until the crust is golden brown and the filling is bubbly. Let cool before serving.