Cream butter and sugar; add vanilla, salt and egg yolks, beating till light and fluffy. stir in flour and blend well. Cover and chill 30 minutes or till firm enough to handle.
Preheat oven to 300° F.
Divide dough into 3 pieces. On lightly floured surface, roll first piece into a 1-inch thick log. Cut log into 3/4-inch pieces and roll each piece into a ball. Repeat entire process with remaining dough.
In small bowl, slightly beat egg white. Dip each ball into egg white, roll in almonds and place 1-inch apart on ungreased cookie sheet. With floured index finger, make a deep indentation in center of each cookie and fill with 1/4 tsp of jam.
Bake for 20 minutes or till golden. Cool on rack.Servings: 3 dozen