Season the popcorn with salt and adjust the seasoning as necessary. Set aside.
Place the butter in a medium saucepan and melt it over medium heat.
Add the sugar into the saucepan and stir until thoroughly mixed. Keep stirring and bring the mixture to a simmer.
Let the mixture cook for roughly 5 minutes without stirring. Add the vanilla at the 4-minute mark and stir.
Continue to simmer the mixture for 1 minute and then add the baking soda.
Pour the caramel mixture over the popcorn. Use a spatula to gently fold the popcorn with the mixture until all are covered.
Transfer to a baking sheet lined with parchment paper. Cover with aluminum foil and let the popcorn cool. Serve and enjoy!
Recipe Notes
To store the popcorn for later, put it in a seal-tight container and place it in the freezer. You want to keep the moisture out and store it in a cool dry place. Storing homemade popcorn this way will help it last long for a week or more.