GREASE 13 x 9-inch baking pan.
HEAT sugar and corn syrup in medium saucepan over medium heat to boiling. Remove from heat; stir in peanut butter. Add cereal; stir until cereal is coated. Press into prepared pan.
MICROWAVE butterscotch morsels in small, microwave-safe bowl on MEDIUM-HIGH (70%) power for 1 minute; STIR. The morsels may retain some of their original shape. If necessary, microwave at additional 10 to 15-second intervals, stirring just until melted. Spread over cereal mixture.
SPRINKLE semi-sweet morsels over butterscotch; press down slightly. Refrigeratefor 15 minutes or until firm.