Pop the corn kernels either in the microwave or on the stovetop
Melt the white chocolate (either in the microwave or using a double boiler)
In a separate bowl, toss together the popcorn, M&M's, pretzels and mini marshmallows
Pour 2/3 of the white chocolate over the mixture and toss until well coated
Using a spatula, spread the trail mix on a parchment-lined baking sheet
Drizzle on the rest of the melted chocolate (I colored mine with chefmaster fat soluble food coloring)
Sprinkle on the unicorn sprinkles
Leave for 30mins or until the chocolate sets
Enjoy!