Preheat the oven to 350 degrees F. Grease a 9-inch square pan with cooking spray and line with parchment so that wings come up the sides by 1 inch.
In a large pot, combine the sugar, corn syrup, vanilla and salt over medium heat and cook until the sugar is melted. Stir in the peanut butter, then the cereal. Pour into the prepared pan and pack it down firmly and evenly with a spatula. Scatter the chocolate chips and butterscotch chips all over the top.
Bake until the chips are melty, about 3 minutes. Use an offset spatula to spread the melted chips in an even layer all over the top. Sprinkle with flaky salt and sprinkles if using and allow to set at room temperature or in the fridge. Slice into 25 squares.