1/2 lb. butter
1 1/2 c. sugar
3 egg yolks, well beaten
1 tsp. vanilla
2 1/2 c. flour
1 tsp. baking soda

Cream butter and sugar; add egg yolks. Sift flour and soda together; add to creamed mixture. Roll into 1 inch balls and bake on ungreased cookie sheet at 400 degrees about 10 minutes.