Whip 1 cup heavy cream. Gradually fold in 1/4 cup powdered sugar, 1 egg white stiffly beaten, 1/2 cup macaroons (finely crumbled in blender) and 1 tablespoon sherry. Place mixture in double cupcake papers (large size). Sprinkle top with additional crumbs. Place on tray and freeze. Thaw for approximately 20 minutes before serving.