1 lb. butter
1/4 c. sugar
1 tsp. vanilla
1 c. light brown sugar
2 egg yolks
4 c. flour

Cream butter and sugar; add egg yolks and vanilla; mix well. Blend in flour. Roll into small balls and place on ungreased cookie sheet. Flatten balls with a fork. Bake at 350 degrees for 8-10 minutes. Makes 6 1/2 dozen cookies.