Shortbread Cookies

A friend gave me this recipe last Christmas.  In an effort not to lose it I am posting it here.

1 lb. butter, softened 1 1/2 cups icing sugar Mix above ingredients
1/2 tsp salt 1 tsp vanilla 4 cups flour (3 in mix, 1/2 cup added while kneading, 1/2 cup on flour board)
Mix in all other ingredients & knead. Roll out flat (1/4 inch thick) Cut with round cookie cutter. Press 1/4 Maraschino cherry into center.
Bake at 350 degrees til very lightly browned. (about 12 minutes)