Buttermilk pie

1 1/2 cups sugar
 3 tbsp. all-purpose flour
 1/8 tsp salt
 3 eggs, well beaten
 2 tbsp. melted butter or margarine
 1 1/2 cups buttermilk
 1 tsp vanilla extract
 1 unbaked 9 inch pie shell
 Cinnamon
 Combine sugar, flour, and salt.  Blend in the eggs.  Add butter, 
 buttermilk, and vanilla, and mix very well.  Pour into the pie shell and 
 sprinkle with a little cinnamon.  Bake at 350 degrees for about 35 
 minutes or until the mixture is set.