Start by getting your popcorn ready either by cooking in an air popper, using microwave popcorn, on the stove top or in your instant pot. Set aside 8 cups. Use any extra as a snack as you create this spooky treat.
Add the marshmallows and the butter to a large glass bowl. Microwave on high for 1 minute. Remove the bowl and stir the butter and marshmallow mixture. If the butter has not fully melted or the marshmallows are not completely melted, put it back for an additional 30 seconds.
Mix 2 cups of popped corn into the marsh mallow mixture at a time. Continue to add until all 8 cups are combined.
Spread the mixture onto a cookie sheet with parchment paper or a fancy platter if you prefer.
Sprinkle all of the ingredients over the popcorn mixture evenly and lightly press into the sticky popcorn.
Notes
Marshmallows can be melted with a double boiler if you do not have a microwave.