Ingredients:
1/2 cup butter, softened
1/4 cup packed brown sugar
1 egg yolk (discarding the white or saving it for another use)
1/2 teaspoon vanilla
1 cup flour
2/3 cup jam
1/4 teaspoon salt
Directions:
Preheat oven to 350. Grease cookie sheet. Cream butter, sugar and egg yolk . Add vanilla, flour and salt and mix well. Shape dough into balls, place on cookie sheets 2 inches apart. Bake 5 minutes. Remove from oven, dent each cookie and fill with preserves. Bake for 8 additional minutes then remove to rack to cool.