Preheat oven to 250 degrees F. Line a baking sheet with parchment paper.
Pop your popcorn by following the instructions on the kernels.
Spray a large bowl with cooking spray. Pour popped corn in.
Mix together brown sugar, corn syrup, butter, salt , and water in a medium saucepan.
Simmer stirring frequently until the temperature reaches 250 on a candy thermometer.
Remove from heat. Stir in vanilla and baking soda.
Pour caramel mixture over the popcorn. Fold in until popcorn is evenly coated. Stir in peanuts.
Pour popcorn onto prepared baking sheet in a single layer.
Bake for 1 hour, stirring every 15 minutes or so.
Cool completely. Break up and store in an airtight container.