Combine flour and salt in a medium mixing bowl; cut in shortening with a pastry blender until mixture resembles coarse meal. Sprinkle 4 to 6 tablespoons cold water over flour mixture; stir with a fork until dry ingredients are moistened. Shape dough into a ball; chill.
Roll half of pastry to 1/8-inch thickness on a lightly floured surface; fit pastry into a 9-inch pieplate. Place apple slices in pieplate; sprinkle with 2 tablespoons water.
Roll remaining pastry to 1/8- inch thickness, and place over apple slices. Trim edges; seal and flute. Cut several long slits in top crust. Bake at 375° for 55 minutes or until golden brown. Remove from oven; set aside.
Combine 2 tablespoons water, sugar, butter, and cinnamon in a small saucepan; bring to a boil. Pour syrup into pie through slits in top crust. Cool pie before cutting.