Cook the sugar and Karo syrup together until it boils.
Then remove from heat. Add the peanut butter and stir til well blended. Then add your rice Krispies. (You'll want to use a BIG bowl). Stir in and press into a greased 9 x 13 pan.
Melt and spread on top- 1 cup milk chocolate chips and 1 cup butterscotch chips. I just melt them in my glass measuring cup in the microwave. Don't over melt them or it will seize.