1. Combine popcorn and chopped BUTTERFINGER® in large bowl.
2. Melt butter in medium saucepan over low heat. Stir in marshmallows. Heat mixture, stirring constantly, until marshmallows are melted and the mixture is smooth.
3. Pour over popcorn mixture and quickly toss to coat well. Spray your hands with non-stick cooking spray. Form the popcorn mixture into six 3-inch balls and place on wax paper to cool. Store in airtight container.