Place pop tarts in a large ziploc bag and use a rolling pin to roll over the pop tarts and crush them, transfer the crushed pop tarts to a stand mixer fitted with a whisk attachment or large bowl.
Add in 3/4 cup of the white frosting and beat in a stand mixer or with a hand mixer until combined.
Line a large cookie sheet with parchment paper and use a 1 tablespoon cookie scoop to scoop out evenly sized balls, roll between your palms and place the balls on the lined baking sheet and place in the fridge for 15 minutes.
Meanwhile, microwave the other container of frosting or melt the candy melts on 30 second intervals until smooth, stirring in between.
Use a fork to dip the balls in the frosting or melted candy and use a toothpick or paring knife to slide the balls off and back onto the baking sheet, repeat for all truffles. Sprinkles the dipped balls with rainbow sugar sprinkles.
If using the frosting, place in the fridge for 30 minutes. If using candy melts, allow them to harden at room temp.