Yugoslavian Christmas Cookies
["1 cup butter, softened", "1 - 1/2 cups sugar, divided", "1 egg yolk", "1/2 teaspoon salt", "2 - 1/2 cups flour", "4 egg whites", "3/4 cup nuts, chopped", "1 teaspoon lemon extract", "1 cup blackberry jelly"]
["Cream butter with 1/2 cup sugar; add egg yolk and salt. Stir in flour. Pat mixture into 10 x 15 inch pan. Stir jelly over dough. Beat egg whites until stiff but not dry.", "Add remaining cup of sugar, beating slowly. Fold in most of nut and the lemon extract. Spread meringue over jelly. Top with the rest of the nuts."]
["butter", "sugar", "egg yolk", "salt", "flour", "egg whites", "nuts", "lemon", "blackberry jelly"]