Put creamy peanut butter and marshmallow cream in a bowl. Mix together until combined.
Stir in the rice krispies.
Line a 9×9 inch pan with enough foil so that it hangs over the sides a bit. Add the dough. Use a rubber spatula to flatten the peanut butter bars. To make them smooth on the top, use an offset spatula.
To make the frosting for the peanut butter bars, put chocolate chips and butterscotch chips in a microwave-safe bowl. Melt in the microwave on high for 45-seconds. Stir until smooth. If needed, microwave for 15-second intervals and stirring after each interval.
Scrape the melted chocolate onto the bars. Spread the chocolate frosting over the bars.
Put the peanut butter bars in the fridge to allow the chocolate frosting to harden and set. Use the foil to lift out the bars and cut them into pieces.