Popcorn ball recipes for Halloween are widely available on recipe websites. EatingWell offers a healthy recipe, What's Cooking America features an old-fashioned recipe, and Martha Stewart has a video tutorial.
An easy Halloween popcorn balls recipe from About.com calls for lining a baking sheet with aluminum foil and spraying it with cooking spray. Pop 1 bag of plain popcorn, making 12 cups total. Place the popcorn and 1 1/2 cups candy corn in a large bowl. Mix well.
Microwave 1/2 stick of butter until melted. Add 4 cups miniature marshmallows, and microwave the mixture until the marshmallows melt. Add 1 teaspoon vanilla and 1/4 teaspoon salt. Stir the mixture well, and pour it over the popcorn and candy corn. Use a large spoon to stir until the popcorn is well covered.
Let the melted mixture cool for a minute. Meanwhile, coat hands with nonstick cooking spray. Scoop up the desired amount of popcorn, and form into a ball. Press firmly so that it sticks together. Set the popcorn balls onto the baking sheet, and allow to cool completely.
Both the healthy and old-fashioned recipes call for replacing the marshmallow mixture with caramel. Combine 1/4 cup light corn syrup, 2 tablespoons butter and 1/3 cup brown sugar in a saucepan. Heat on medium, stirring constantly, until the mixture melts and bubbles. Use this to coat the popcorn and candy corn.