Layer all of the ingredients in the bottom of a 6-quart slow cooker then stir to combine.
Cover the slow cooker and heat on low for about 2 hours, stirring every 20-30 minutes, and stopping when all of the chips are melted.
Line two large baking sheets with parchment paper or silicone baking mats. Set aside.
Using a spoon or cookie scoop, drop mounds of the clusters onto the baking sheets.
Allow to set up at room temperature until completely hardened, about 1 to 2 hours.
Store leftovers in an airtight container for up to 1 month. Clusters freeze well, up to 3 months. Thaw at room temperature.
