Stir together oats, half of the poppy seeds, salt and 1/2 cup hot water.  Let stand for about 10 minutes or until lukewarm.

In food processor, pulse prunes, cranberries and walnuts until finely chopped, but not pureed; stir into oats mixture along with lemon zest and lemon juice.  Knead until well combined.  Roll into 12 balls.

Roll balls in remaining poppy seeds.  Refrigerate in airtight container for 3 days, or free for up to 4 weeks (defrost at room temperature for at least 3 hours before serving).