Add the sugar gradually to the pumpkin puree. Beat well an stir in the flour, salt and spices. Stir in the corn syrup and beat well. Stir in the slightly beaten egg, then slowly add the evaporated milk, mixing until well blended. Pour the batter into the unbaked pie shell.
Bake at 450 degrees F (230 degrees C) for 10 minutes then reduce the oven temperature to 325 degrees F (165 degrees F) and continue baking pie for an additional 30 minutes or until a knife inserted into the mixture comes out clean.