Dark Chocolate Caramel Popcorn (Moose Munch Copycat)

Dark Chocolate Caramel Popcorn - this is a customizable copycat recipe for Harry & David's Moose Munch. Just try not to eat it all in one sitting - sooo good.
Ingredients
- 12 cups popped popcorn
 - 1.5 cups nuts of choice (peanuts, pecans, cashews, etc)
 - 1 cup firmly packed brown sugar
 - ¾ cup butter
 - ½ cup light corn syrup
 - 1 tsp baking soda
 - 1 cup dark chocolate chips
 - 1.5 tsp shortening
 
Instructions
- Preheat oven to 250F
 - Spread popped popcorn and nuts into a large roasting pan, or divide between two pans.
 - In a heavy bottom saucepan, combine brown sugar, butter, and corn syrup. Cook over medium heat for about 8 minutes, or until mixture comes to a boil.
 - Continue boiling for 2 minutes.