Spray a 9 by 13 inch pan with nonstick spray and line with parchment paper.
In a small saucepan, heat peanut butter, brown sugar and corn syrup. Stir until melted. Pour the rice cereal into a large bowl and stir in the peanut butter mixture. Press into the bottom of the pan.
Over a double boiler melt the butterscotch morsels and chocolate morsels. Spread the mixture over the cereal bars and sprinkle with chopped peanuts. Press peanuts into the topping. Let sit until cooled and firm, about 2 hours.