In a medium saucepan, combine the corn syrup, peanut butter, and sugar. Heat over medium, stirring until the mixture is melted, smooth, and pourable—do not bring to a boil.

Pour the warm peanut butter mixture over the cereal in a large bowl and stir until the cereal is evenly coated.

Use a medium cookie scoop (about 2 Tbsp size) to scoop clusters onto a baking sheet lined with parchment or wax paper. Allow clusters to cool slightly.

Melt the semisweet chocolate chips and butterscotch chips together—either in a double boiler or in the microwave. If using a microwave, heat for 30 seconds, stir, then heat again for 15–20 seconds, stirring until smooth and creamy. Avoid overheating.

Spoon the melted chocolate–butterscotch mixture over each cluster.

Let the clusters sit at room temperature until the chocolate and butterscotch coating hardens.