Place your M&Ms into the freezer and then line a sheet pan with wax or parchment paper. Set the sheet pan aside.

Add 10 cups of popcorn to a large mixing bowl. If your popcorn is unsalted, sprinkle with 1 teaspoon of kosher salt.

In a 2 quart or larger saucepan, melt the butter over medium high heat.

Once melted, reduce the heat to medium and add the mini marshmallows. Heat the mixture over medium heat, stirring constantly, until the marshmallows are just melted. Do not boil.

Remove the pan from the heat and immediately pour the marshmallow mixture over the popcorn.

Use a rubber spatula to mix and coat the popcorn in the marshmallow goo evenly.

Pour the mixture out onto the parchment paper lined sheet pan. Allow the mixture to cool slightly, going from hot to warm, the mixture should still be quite sticky.

Grab your M&Ms from the freezer and sprinkle evenly over the sticky popcorn mixture.

Allow the mixture to cool to room temperature and then scoop out portions the size of a heaping 1/3 cup.

Mold the scoops of popcorn and M&Ms into neat balls. Compress the popcorn balls tightly so that they keep their shape. It's natural for the M&M's to break lightly or get a little melty during this process, totally ok!

Next, pour the Halloween sprinkles into a small bowl and roll each popcorn ball in the sprinkles, pressing down lightly to adhere. Shake off any spots with too many sprinkles. At this point you can also press additional M&M's onto the outside of each ball or additional edible Halloween decorations. Repeat this process until all popcorn balls are sufficiently decorated.

Serve the popcorn balls immediately or package for handing out.