Ingredients:
1 cup butter, softened
1/2 cup packed brown sugar
1 egg yolk
1 teaspoon vanilla extract
1 cup all-purpose flour
1/2 cup chopped walnuts
2/3 cup any flavor fruit jam
1/4 teaspoon salt
Directions:
Preheat oven to 320º. Grease cookie sheets.
Cream butter, sugar, and egg yolk together. Add vanilla, flour, walnuts, and salt. Mix well.
Shape dough into balls. Place on cookie sheets about 2 inches apart. Bake for 5 minutes.
Remove cookies from oven. With thumb, dent each cookie. Put jelly or preserves in each thumbprint. Bake for another 8 minutes.