2 1/2 c. flour
1 1/4 c. sugar
1 tsp. vanilla
1/2 tsp. cream of tartar
1 tsp. baking soda
1 c. butter
3 egg yolks

Beat together butter, sugar and egg yolks until fluffy. Add vanilla. Add dry ingredients gradually. Chill dough about an hour. Shape into balls and roll in sugar. Bake about 10 to 12 minutes on greased cookie sheet at 350 degrees. I double this recipe.