Line a 15-in. x 10-in. baking pan with waxed paper; grease the paper and set aside.
In a large microwave-safe bowl, combine the marshmallows, butter and peanut butter. Cover and microwave on high for 1 1/2 minutes; stir until well blended.
Stir in cereal until well coated. Spread into prepared pan. (Grease hands well to pat down the rice cereal mixture)
In a microwave-safe bowl, combine chocolate chips and butterscotch chips. Microwave, uncovered, on high for 1 1/2 minutes. Stir; spread over cereal mixture to within 1-inch of edges. Roll up jelly-roll style, starting with a short side, peeling waxed paper away while rolling. Place seam side down on a serving plate. Refrigerate for 1 hour or until set. Cut into 1-inch slices.