01 - Line two baking sheets with parchment paper or silicone mats for easy cleanup and removal.
02 - Combine chocolate chips, butterscotch chips (if using), and butter in a large microwave-safe bowl. Microwave in 30-second intervals, stirring after each, until fully melted and smooth, approximately 1–2 minutes total.
03 - Allow the melted mixture to cool slightly for 2–3 minutes, then fold in peanuts and marshmallows until evenly coated.
04 - Using a tablespoon or small cookie scoop, drop mounds of the mixture onto prepared baking sheets, spacing them about 1 inch apart.
05 - Let clusters set at room temperature for 2 hours or refrigerate for 30–40 minutes until firm.
06 - Store in an airtight container at room temperature for up to 1 week.