Grandma Mary'S Butter Cookies
["1 c. sweet butter", "1 c. granulated sugar", "3 egg yolks", "2 1/2 c. sifted flour", "1 tsp. vanilla"]
["Cream butter.", "Beat into sugar.", "Add egg yolks and vanilla. Beat well after adding each yolk.", "Add flour and beat after each 1/2 cup is added.", "Chill about 1 hour."]
["sweet butter", "sugar", "egg yolks", "flour", "vanilla"]