01 - Line two baking sheets with parchment paper or silicone mats to prevent sticking and ensure easy cleanup.
02 - Combine chocolate chips, butterscotch chips (if using), and butter in a large microwave-safe bowl. Microwave in 30-second intervals, stirring after each interval, until completely melted and smooth, approximately 1–2 minutes total.
03 - Let the melted mixture stand for 2–3 minutes to cool slightly, which prevents marshmallows from melting too quickly when added.
04 - Gently fold peanuts and marshmallows into the chocolate mixture until evenly coated, being careful not to crush the marshmallows.
05 - Using a tablespoon or small cookie scoop, drop mounds of the mixture onto prepared baking sheets, spacing approximately 1 inch apart to allow for even setting.
06 - Allow clusters to set at room temperature for 2 hours, or refrigerate for 30–40 minutes until firm. Store in an airtight container at room temperature for up to 1 week.