Process almonds and sugar until fine and powdery. Add 1 egg white. Beat, and
add additional egg white slowly until a paste forms that holds together (may not
need all of it). Turn out onto floured surface, form a ball, turn to flour all sides.
Shape into an 11-inch long cylinder. Place on cookie sheet, brush off excess flour.
Dip finger in water, press a trench into dough, lengthwise. Don't cut through
the ends. Stand uncovered overnight.
Stir preserves well. Place in trench, top with sliced almonds.
Bake 25 to 28 minutes at 350 degrees F, or until macaroon is lightly colored
and preserves start to bubble.
Cool, sprinkle with confectioners' sugar. Cut
into diagonal slices.