Combine the flour and salt in mixing bowl. Cut room temperature shortening into flour until mixture is uniform and shortening resembles large peas. Beat egg, water, and vinegar together to blend. Pour all of the liquid evenly over flour mixture. Stir in with fork until all of the mixture is moistened. Divide dough in half and shape each into a ball. Flatten each into a 4-inch circle. Wrap and chill dough for 15 minutes for easier rolling.
Dust rolling pin and work surface lightly with flour. Roll dough to a uniform thickness. Roll to a circle about 1-inch larger than upside down 8-inch pie plate. Carefully place one dough circle into pie plate and gently press into form of plate. Trim excess dough around the edge with the back of a knife.
Preheat oven to 400 degrees F.
Peel, core, and slice apples. Mix apple slices with sugar, flour, and cinnamon. Place apple mixture in pie shell. Place second pie crust on top and form to the edges of the pie plate. Cut slits in the top crust to allow for steam to release in oven. Bake for approximately 30 to 40 minutes, until pie is fully baked and apples are tender.