In a large bowl, cream butter, peanut butter and confectioners' sugar; stir in cereal. Divide dough in half. Cover and refrigerate 1 hour or overnight. Working with half of dough, scoop into tablespoonfuls and shape into 1/2-in.x2-in.-thick logs. Place on waxed paper-lined pans., In a microwave-safe bowl, melt chocolate chips; stir until smooth. Dip or drizzle over logs. If desired, sprinkle with peanuts. Chill until set. Repeat with remaining dough. Store in an airtight container in the refrigerator.