Butter Cookies
["1 lb. butter", "1 c. sugar", "4 1/2 c. sifted flour", "2 whole eggs", "2 egg yolks", "2 or 3 tsp. vanilla"]
["In mixer bowl, cream sugar and butter, then add beaten eggs, then flour gradually.", "Add vanilla to taste.", "Bake at 350\u00b0 for 20 minutes."]
["butter", "sugar", "flour", "eggs", "egg yolks", "vanilla"]