Combine the flour and salt in a medium mixing bowl. Work the butter into the flour mixture using your hands or a pastry cutter until the mixture resembles coarse crumbs. Add water one tbsp at a time until dough forms.
Pull the dough for the crust together into a ball. Flatten it into a disk and wrap it with plastic wrap. Refrigerate while you make the pie filling. (chill for at least 30 minutes).
Rollout pastry dough into pie tin. Pour in pumpkin pie filling. Bake for 15 minutes. Reduce the oven temperature to 350 degrees. Continue baking for an additional 35-40 minutes or until a knife inserted in the center of the pie returns clean.