Roll out pastry on lightly floured wax paper into a 13 1/2-inch circle with a
floured rolling pin. Invert the pastry over a 9-inch deep-dish pie pan. Peel off
the paper. Gently tuck the pastry down into the pan without stretching it. Flute
edges. Chill the pie shell in the freezer at least 30 minutes.
For the filling, mix the apples, sugar, lemon zest, cinnamon and cardamom in a
large mixing bowl; set aside 10 minutes. Heat the oven to 400°F.
Sprinkle the flour over the apples; mix well. Turn the filling into the frozen
pie shell. Put the pie on a baking sheet covered with foil; bake 30 minutes.
Reduce the oven temperature to 375°F. Place foil over pie. Bake 20 minutes.
Meanwhile, for sour cream topping, whisk ingredients together in a medium-sized
bowl. Set aside. For graham cracker topping, put graham crackers and sugar in a
food processor; process into fine crumbs. Transfer crumbs to a small bowl; stir
in cinnamon and melted butter. Stir mixture with a fork; rub it between your
fingers to make a uniform mixture. Refrigerate.
Reduce the oven temperature to 350°F. Pour or spoon the sour cream topping over
the pie, spreading it with the back of a spoon. Carefully put crumbs in the
center of the pie, spreading them evenly over the surface with your hands. Bake
until crumbs are toasted, 7-8 minutes.
Cool pie on a rack. Loosely cover pie with foil; refrigerate 2 hours before
serving.
