In a large bowl, combine pumpkin, evaporated milk, eggs, sugar, flour, salt vanilla and cinnamon. Pour filling into pie shell.
Bake for 20 minutes at 450 degrees F (230 degrees C) then turn oven temperature down to 350 degrees F (175 degrees C) and continue baking 40 more minutes or until a knife inserted in center comes out clean. Cool completely on a wire rack before serving.
