In a large pot, melt butter over medium heat. Add marshmallows and stir until melted. Add in white chocolates. Remove from heat and stir until smooth. Add popcorn and gently stir until evenly coated.
Pour out onto a cookie sheet lined with parchment paper. Sprinkle on half of the sprinkles.
Using buttered hands, form popcorn into one balls for mini bites or two inch ball for regular size. Add additional sprinkles as necessary to each ball to make pretty.