Butter Cookies
["1 lb. butter or margarine", "1 1/4 c. sugar", "2 egg yolks", "4 c. flour", "1 tsp. vanilla"]
["Cream butter with mixer and add sugar, beating until fluffy. Add vanilla and egg yolks; beat well.", "Add flour a little at a time with a large spoon, mixing well.", "Shape into walnut size balls. Flatten slightly with bottom of a glass if desired.", "Bake at 350\u00b0 for 15 minutes.", "They will not be brown; only bottom edges should be slightly brown."]
["butter", "sugar", "egg yolks", "flour", "vanilla"]