To prepare crust: Combine 1 cup plus 2 tablespoons flour and the salt in a large bowl or food processor. Cut in cold shortening using a pastry blender, two knives or by pulsing in the food processor until pebble-size pieces form. Add ice water, 1 tablespoon at a time, until the dough is evenly moist (but not wet) and is just starting to clump together. Pat the dough into a 5-inch disk. Lightly flour a large sheet of plastic wrap, place the dough in the center and wrap it up. Refrigerate for at least 1 hour and up to 2 days. Remove from the refrigerator about 15 minutes before rolling out.

Meanwhile, prepare filling: Combine apples, 1/2 cup brown sugar, lemon juice and 1/2 teaspoon cinnamon in a large bowl. Let stand for at least 10 minutes. Add cornstarch and toss to coat.

Preheat oven to 375 degrees F.

Roll the dough into a 12-inch round between two pieces of parchment paper. Remove the top sheet; gently invert the dough into a 9-inch pie pan (not deep-dish). Remove the second sheet of parchment. Trim the dough to an even overhang all the way around. Patch any cracks with the extra dough. Fold the dough under to form a double layer of crust around the edge. Crimp the edges. Mound the filling into the crust. Bake the pie for 20 minutes.

Meanwhile, prepare topping: Combine oats, flour, brown sugar and cinnamon in a medium bowl. Cut in shortening with a pastry blender or two knives.

Sprinkle the topping over the pie and continue baking until the filling is bubbling and the crust and topping are golden, about 40 minutes more. Cool for at least 1 hour before serving.