Thumbprint Cookies

1 cup butter
1 cup sugar
2 egg yolks
1 tsp vanilla
2 cups flour
¼ tsp salt
2 egg whites
2 cups pecans, chopped fine

Cream butter, sugar, egg yolks and vanilla.  Mix flour and salt and stir into creamed mixture.  Chill dough.  Roll 1 tsp dough into balls.  Dip in slightly beaten egg whites and roll in nuts.  Place on baking sheet and press finger into center of each.  Bake at 10-12 minutes at 350°.  Fill cooled cookies with 1 tsp. jam of choice.  Makes 6 dozen.
Variation:  add 2 squares melted unsweetened chocolate to dough and fill centers with chocolate frosting.