Start by popping your popcorn. If you’re using a stovetop method, heat a large pot over medium heat and add your popcorn kernels. Cover the pot, and shake it occasionally until the popping slows down. Once done, transfer the popped popcorn to a large mixing bowl. If using a popcorn maker, simply follow the manufacturer's instructions.
In a microwave-safe bowl, combine the butterscotch chips, white chocolate chips, and coconut oil. Microwave in 30-second intervals, stirring in between until melted and smooth. Be careful not to overheat, as this can cause the chocolate to seize.
Once the chocolate mixture is melted, pour it over the popped popcorn. Use a spatula to gently fold the popcorn until it's evenly coated. If you’re adding nuts, fold them in at this stage.
Spread the coated popcorn onto a large baking sheet lined with parchment paper. This will help prevent sticking. Allow it to cool completely so that the chocolate can harden.
Once cooled, break the popcorn into clusters and serve in bowls or store it in an airtight container for later.