1Lightly spray 9-inch square pan with cooking spray.
2In deep large saucepan, melt 2 tablespoons of the butter over medium heat. Add peanut butter, syrup and marshmallows. Cook and stir until marshmallows are melted. Add cereal and 1 cup popped amaranth; stir until well coated. Press into pan.
3In small microwavable bowl, microwave chocolate chips, butterscotch chips and remaining 1 tablespoon butter uncovered on High about 1 minute, stirring once, until melted and smooth. Spread over bars. Sprinkle with additional popped amaranth. Cool. Cut into 3 rows by 3 rows.