To make the Popcorn:
Add oil to a large pot and heat over medium heat.
Add the kernels to the pot and spread evenly. Place the lid over the pot.
Once the popping has slowed down to about a few seconds between pops, remove from the heat.
Release the steam and re-apply the lid to keep the popcorn warm while preparing the caramel.
To make the Caramel:
Preheat oven to 250 degrees.
In a medium-sized pot, melt the butter over medium-low.
Once the butter is melted stir in the brown sugar, corn syrup, and salt.
Stir together then allow the caramel to thicken (approximately 2-4 minutes).
Remove from the heat and stir in the vanilla and baking soda.
Pour the caramel over the popcorn and stir together evenly coating the popcorn with the caramel.
Once coated, spread the popcorn onto a baking sheet lined with parchment paper.
Bake for approximately 45 minutes, tossing occasionally for crunchy popcorn.
For a Softer Texture: If you prefer a chewier, less crunchy caramel corn, reduce the baking time to 35 minutes.
Remove from the oven, break up any large clumps into smaller pieces if desired and allow to cool completely.
Once cooled, serve/store in an airtight container.