Jam Thumbprints
["2/3 c. butter", "1/3 c. sugar", "2 egg yolks", "1 tsp. vanilla", "1/2 tsp. salt", "1 1/2 c. flour", "2 egg whites", "3/4 c. chopped walnuts", "1/3 c. favorite jam"]
["Cream together butter and sugar until fluffy.", "Add egg yolks, vanilla and salt.", "Beat well.", "Gradually add flour, mixing well. Shape into 3/4-inch balls.", "Dip in slightly beaten egg whites, then roll in chopped walnuts.", "Place 1-inch apart onto greased cookie sheet.", "Press down center on each with thumb.", "Bake at 350\u00b0 for 15 to 17 minutes.", "Cool slightly.", "Remove from pan and cool on rack.", "Just before serving, place jam in center of cookie.", "Makes 3 dozen."]
["butter", "sugar", "egg yolks", "vanilla", "salt", "flour", "egg whites", "walnuts", "favorite jam"]