Preheat the oven to 200 degrees, line a large baking sheet with parchment paper and set aside.
In a large saucepan, add the brown sugar, butter, corn syrup, and salt and cook on medium heat for about 5 minutes.

Remove from heat, add the vanilla and baking soda and pour the mixture over the popcorn and stir everything together.
Tumble the mixture on your prepared baking sheet and spread in a thin layer, bake them for 1 hour giving them a stir every 20 minutes.

Allow them to cool at room temperature then break them up into bits once cooled.