Pop the popcorn however you like. You can use an air-popper or pop it on the stove, whichever is easiest for you.

Place the popped corn in a very large bowl.

In a large pot add the butter and melt over medium heat.

When the butter is melted add the mini marshmallows and cook, stirring constantly, until the marshmallows melt and the mixture is a thick consistent texture.

Remove from the heat and stir in the salt and vanilla.

Pour the melted marshmallow mixture over the popcorn in the prepared bowl. Mix well to combine.

Grease your hands with a bit of butter and use your hands to form the mixture into balls, gently pressing the sticky popcorn mixture into shape. 

Place finished popcorn ball on a piece of parchment or waxed paper.

Repeat with remaining popcorn until you've used it all and made around 10 popcorn balls. 

Serve right away or store in a single layer in an air-tight container for up to 1 day before serving.