
In a saucepan over medium high heat, combine brown sugar, corn syrup, butter, and salt.
Whisk until the sugar and butter have melted.
Continue to whisk 1 to 2 minutes after they've melted to create the caramel sauce.
Place 11 cups of popped popcorn in a large deep roasting pan and sprinkle the peanuts over the popcorn.
Pour the caramel sauce over the popcorn and turn to coat.
Place in the preheated oven (250°F) and remove the pan every 10 to 15 minutes to stir the popcorn to recoat it with caramel. Repeat 3 to four times until the caramel has cooked about 45 minutes to total.