Preparation Steps

• Line 2–3 rimmed baking sheets with parchment or waxed paper. Preheat the slow cooker on LOW for 10 minutes while you gather ingredients.
• Add the dark, semi-sweet, and white chocolate chips to the slow cooker along with the peanut butter and espresso powder (if using). Place a clean kitchen towel under the lid to catch condensation, then cover.
• Cook on LOW for 50 minutes without stirring. Uncover, remove the towel, and stir slowly but thoroughly, scraping the bottom and sides to combine.
• Continue on LOW for 15–20 minutes more, stirring once or twice, until the mixture is completely smooth and glossy. Switch the cooker to WARM, then stir in the vanilla off heat to preserve its aroma.
• Fold in the peanuts in two additions until every nut is evenly coated. If the mixture thickens as you work, keep the lid on between folds to retain warmth.
• Using a 1-tablespoon scoop or two small spoons, drop mounds onto the prepared sheets. Keep the slow cooker on WARM and give the mixture a quick stir every few minutes to maintain fluidity while portioning.
• Let the clusters set until firm—45–60 minutes at room temperature, or 20–30 minutes in the refrigerator. Once set, transfer to an airtight container.