*Popcorn can be air popped to reduce fat or popped in oil, your choice. *Popping the popcorn in oil will help the caramel corn to separate easily.
*Remember to remove any un-popped popcorn kernels.
Preheat oven to 250 degrees. Lightly spray a large roasting pan with a non-stick cooking spray. Place popped popcorn in prepared pan.
Prepare caramel sauce: In a heavy-bottomed medium saucepan over medium-low heat, combine the brown sugar, corn syrup and butter, stir until smooth and melted. Increase heat to medium, stirring constantly until the caramel sauce comes to a boil. Boil for 5 minutes only, stirring constantly (let boil for 5 minutes only or until temperature reaches 235 degrees on your candy thermometer) Immediately remove from heat. Carefully stir in the vanilla extract, baking soda and salt (mixture will begin to boil violently) Using a long-handled wooden spoon, stir down the mixture until rolling boiling subsides. Pour the hot caramel syrup over popcorn stirring evenly to coat; place the roasting pan in the oven.
Bake for 1 hour and 30 minutes, stirring every 20 minutes. Remove from the oven and carefully pour popcorn onto a large sheet of tin foil (mix caramel popcorn with the cheese popcorn).
Let cool completely. Once cool, break apart any large clumps with your hands. Store in airtight containers or in ziplock baggies