1.Preheat oven to 250 degrees
2.Prepare popcorn using the directions on the bag. Line a cookie sheet with non stick foil and spray with cooking spray. Inspect the popcorn and remove any un-popped kernels. Place in the preheated oven.
3.In a medium saucepan, combine the brown sugar, corn syrup, butter and salt. Cook over medium heat. Bring to a boil and stir continually (we don’t want this to burn).
4.After it boils, turn the heat down to low and do not stir for 3-5 minutes. You may want to take a heat proof rubber spatula and scrape down the sides of the saucepan if needed.
5.Remove from the heat, stir in the vanilla extract and baking soda.
6.Pour the mixture over the popcorn and toss to coat entirely.
7.Bake about 35-50 minutes, stirring every 10 to 15 minutes. This is an important step so the popcorn does not burn.
8.When finished, cool completely. You may want to break apart some of the larger pieces before serving