In a large pot over medium heat, combine the granulated sugar and light corn syrup. Stir continuously until the mixture comes to a boil.
Once boiling, remove the pot from heat and stir in the peanut butter until smooth and well-combined.
Add the Rice Krispies cereal to the peanut butter mixture, stirring gently until all the cereal is fully coated.
Line a 9x13 inch baking dish with parchment paper for easy removal. Pour the cereal mixture into the dish, pressing it down firmly and evenly using a spatula or your hands.
In a microwave-safe bowl, combine the semisweet chocolate chips, butterscotch chips, and a pinch of sea salt. Microwave in 30-second intervals, stirring in between, until the chips are completely melted and the mixture is smooth.
Pour the melted chocolate-butterscotch mixture over the pressed cereal layer, spreading it evenly with a spatula.
Allow the scotcheroos to cool at room temperature for about 1 hour or until the topping sets.
Once set, lift the scotcheroos out of the baking dish using the parchment paper. Cut into squares or bars.
Notes
Arrange the Scotcheroos in a decorative platter and drizzle some extra melted chocolate or butterscotch over them for an added touch of indulgence.