In an air popper, pop the kernels according to your machine’s manual. My machine only allows you to pop 1/3 cups at a time, so make sure you follow your machine’s capacity instructions. You should have almost 4 quarts of popped popcorn using 1/2 cup of kernels.

Dump the popcorn and the Spanish peanuts in a clean tall paper grocery bag. Preheat oven to 300 degrees F. In a medium sauce pan, combine brown sugar, corn syrup, butter, and salt over medium heat and allow to gently boil for 5 minutes, stirring occasionally.

Turn off heat and stir in baking soda and vanilla. Carefully and immediately pour caramel sauce into the paper grocery bag and stir the sauce, popcorn, and nuts with a wooden spoon until the sauce is evenly distributed. Take the popcorn mixture and evenly scatter it between both greased cookie sheets.

Bake for 45 minutes, stirring the popcorn every 15 minutes. Remove from the oven and sprinkle with sea salt. Allow to cool and break up the pieces (if desired). Store in Ziploc bags or airtight containers. Enjoy!