Butter a 9x13-inch baking pan or line with parchment paper and set aside. Pour cereal into a large bowl.

In a small saucepan, combine sugar and corn syrup and bring to a boil, stirring to dissolve sugar completely.

Once boiling, remove from heat. Whisk in peanut butter and vanilla until well blended and smooth. Pour over the cereal and mix until coated.

Scoop into prepared baking pan and press gently but firmly to the edges.

Combine chocolate chips and butterscotch chips in a microwave-safe bowl and microwave in 30-second increments, stirring after each time, until nearly melted. Stir to melt completely and blend, then pour over the bars and spread to the edges.

Let cool completely, until topping has hardened. Slice and serve.