Pop your popcorn according to package directions, try to discard as many unpopped kernels as you can and place in large bowl, set aside.

In a large pot melt your butter then add your marshmallows and stir until melted and smooth then add in vanilla and stir.

Pour mixture over popcorn and toss to coat trying to get all kernels.

Let cool slightly and then grab enough popcorn to create baseball or softball sized balls and gently press together and place into cupcake liners if desired.

Immediately sprinkle with sprinkles.