2/3 c. butter
1/3 c. sugar
2 egg yolks (save egg whites)
1 tsp. vanilla
1/2 tsp. salt
1 1/2 c. flour
Fruit jam

Cream together butter and sugar. Add egg yolks, vanilla and salt. Beat well. Gradually add flour. Shape into balls, dip in egg white, place on cookie sheet 1 inch apart. Push down center with thumb to form a "crater". Bake at 350 degrees for 15 to 17 minutes. Cool slightly. Spoon a small amount of jam in the center.