Popcorn Balls

Ingredients
2 quarts popped popcorn
1 cup packed brown sugar
1/3 cup water
1/3 cup dark corn syrup
1/4 cup butter (no substitutes)
1/2 teaspoon salt
1 teaspoon vanilla extract
Directions
Place popcorn in a large bowl; set aside. In a heavy saucepan, combine brown sugar, water, corn syrup, butter and salt. Bring to a boil over medium heat, stirring constantly. Continue cooking, without stirring, until a candy thermometer reads 270 degrees F (soft-crack stage).
Remove from the heat; stir in vanilla. Pour over popcorn; stir until evenly coated. When cool enough to handle, quickly shape into balls