In a large mixing bowl with electric mixer, beat butter, cream cheese, egg yolk,
vanilla extract and lemon peel until well blended. Mix in confectioners' sugar,
then flour to make a stiff dough.
Shape chilled dough into 30 small balls. Beat egg white until foamy. Dip balls
into egg white, then roll in nuts. Place balls on lightly greased baking sheets. Press
an indentation into the center of each ball; fill with a little raspberry jam.
in a preheated 350 degree F oven for 10 to 15 minutes, or until cookies begin to
brown on the bottom.