Sour Cream Frosting
["1 1/2 c. sugar", "1/4 tsp. salt", "1 c. sour cream", "3 Tbsp. butter"]
["Mix and boil until soft ball forms in cold water. Before removing from stove, add 3 tablespoons butter. Remove from stove and let cool. Do not stir until cold.", "Beat."]
["sugar", "salt", "sour cream", "butter"]