Preheat oven to 250.
Line a baking sheet with parchment paper.
Pop the popcorn.
Spray a large bowl with cooking spray add popcorn.
Combine brown sugar, corn syrup, butter, salt and water in a pan.
Simmer over medium-high heat stirring frequently until temperature reaches 250 (firm to hard ball stage).
Remove from heat, stir in the vanilla and baking soda.
Pour over the popcorn and use spatula to gently fold the caramel into the popcorn until well coated.
Stir in the peanuts.
Pour the mixture onto prepared baking sheet and spread out.
Bake for 1 hour, stirring every 15 minutes.
Remove from the oven, and allow to cool.
Carefully break up and store in an airtight container.