In a medium saucepan, combine the butter, brown sugar, corn syrup, molasses and salt. Bring mixture to a boil over medium heat, stirring often. Continue to boil, stirring occasionally, until mixture reaches 265°F (this will take about 3-4 minutes after it starts to boil).

Meanwhile, preheat the oven to 250°F and place the cooked popcorn and peanuts in a large bowl.

Once the caramel mixture reaches 265°F, remove it from the heat and stir in the vanilla extract. Pour mixture it into the bowl with the popcorn and peanuts; stir until well coated. (Note: The caramel mixture will be very sticky, so just stir as well as possible at this stage.)

Transfer popcorn and peanuts to a foil-lined sheet pan and bake for 45 minutes, stirring every 15 minutes. (Tip: I used a large flat turner to help flip the popcorn and peanuts.)

Let mixture cool and add salt to personal taste.