In a heavy saucepan or Dutch oven stir together the light corn syrup and sugar. Over medium heat bring to a boil.
Remove the pan from the heat and stir in the peanut butter until smooth. Add the Rice Krispies and stir until combined.
Pat the mixture into a pan that has been greased with butter.
Frosting
While the bars are cooling add the chocolate chips, butterscotch chips, and peanut butter into a saucepan. Over medium to medium-low melt the ingredients together. Stirring continuously until the ingredients are melt and the mixture is smooth.