Grease a 9x13 baking dish or larger with butter, set aside.
Pop popcorn according to machine instructions and place in the prepared baking dish. Or use ready-made popcorn.
In a large heavy bottomed pot or dutch oven melt butter over medium-low heat.
¼ cup salted butter
Add the marshmallows, stirring occasionally until fully melted. Remove from the marshmallow mixture from the heat and stir in the vanilla extract.
4 cups mini marshmallows, 1 teaspoon vanilla extract
Carefully pour the marshmallow mixture onto the popcorn. Add in the pretzel sticks, half of the Reese’s Pieces and half of the M&Ms. Using a buttered silicone spatula, fold the marshmallow mixture, candy, pretzels and popcorn together. It will be very sticky but just keep going until evenly combined.
12 cups popped popcorn, ½ cup Reese’s Pieces, ½ cup Peanut M&M’s, 1 cup pretzel sticks
Let the mixture cool until it’s comfortable to handle, 3 to 5 minutes.
Generously butter clean hands and scoop out a handful of the mixture and press and roll into a ball. Repeat with remaining mixture. Place popcorn balls on a buttered baking dish or piece of parchment paper.
Press the remaining candy and candy eyeballs onto the popcorn balls to decorate. Let cool completely and enjoy.
½ cup Reese’s Pieces, ½ cup Peanut M&M’s, candy eyes