Line a baking sheet with parchment paper and spray with nonstick cooking spray. Place the popcorn in a large bowl.
Using a double boiler, heat the butterscotch chips until melted, whisking frequently. Whisk in the coconut oil. While warm, pour over the popcorn and stir until coated in the butterscotch mixture. Immediately turn out onto the prepared baking sheet. Press down into an even layer.
Melt the white chocolate chips using the same method as the butterscotch chips, or microwave them until melted. Drizzle the chocolate over the popcorn with a spoon, then sprinkle the crushed peanuts all over. Let the chocolate harden, then break up the brittle before serving.