Bake the cake in a 9x13-inch pan according to the box directions, then let it cool completely on a wire rack, at least 1 hour.

Crumble the cooled cake into a large bowl, add the 3 tbsp vanilla frosting, and mix until the mixture holds together when pressed between your fingers.

Scoop into 20 balls of about 1.5 tbsp each, roll smooth, place on a parchment-lined baking sheet, and freeze for 15 minutes.

Melt 2 tbsp of the candy melts, dip the tip of each lollipop stick into the melt, push it halfway into each cold cake ball, and freeze for another 10 minutes.

Melt the remaining candy melts in 30-second microwave intervals, stir in the 1 tbsp coconut oil, and mix until smooth and pourable.

Dip each pop fully into the coating, let the excess drip off, add a pinch of sprinkles, and stand upright in a foam block or rice-filled glass to set for 5 minutes.