Black And White Cookies
["1 1/2 sticks butter", "1 egg plus 1 yolk", "1 1/2 c. sugar", "2 tsp. vanilla", "3 c. sifted flour", "1/8 tsp. salt", "1 1/2 tsp. baking soda", "1/2 pt. sour cream"]
["Combine butter and eggs.", "Beat until fluffy.", "Add sugar and vanilla. Stir in dry ingredients and sour cream alternately. Bake at 350\u00b0 for 10 to 15 minutes or until brown around the edges.", "Let cool and ice."]
["butter", "egg", "sugar", "vanilla", "flour", "salt", "baking soda", "sour cream"]