Preheat your Oven to 250°F. Line a large rimmed Baking Sheet (or two) with Parchment Paper or a Silicone Baking Mat and set aside.

Pop the popcorn: Heat the 2 tbsp neutral oil such as vegetable in a large, heavy-bottomed Pot over medium-high heat. Add 3 test kernels of ½ cup popcorn kernels unpopped; yields about 12–14 cups popped, cover, and wait until they pop — that means the oil is ready. Add the remaining ½ cup popcorn kernels unpopped; yields about 12–14 cups popped in a single layer, cover, and shake the pot gently every 30 seconds. Once popping slows to about 2 seconds between pops, remove from heat. Transfer popcorn to a very large Mixing Bowl, discarding any unpopped kernels. Add the 1 cup dry-roasted peanuts salted or unsalted and toss to combine.

In a medium heavy-bottomed Saucepan, combine the 1 cup light brown sugar packed, ½ cup unsalted butter cut into pieces, ¼ cup light corn syrup, and 1 tsp fine salt over medium heat. Stir gently until the ½ cup unsalted butter cut into pieces melts and the 1 cup light brown sugar packed dissolves, then bring to a boil without stirring. Let it boil for exactly 4 minutes — it will bubble vigorously and deepen in color. Keep a close eye on it.

Remove the Saucepan from heat. Immediately add the ½ tsp baking soda and 1 tsp pure vanilla extract — the mixture will foam up dramatically, which is normal. Stir quickly to combine. The ½ tsp baking soda creates tiny air bubbles that make the coating light and crispy instead of hard and glassy.

Immediately pour the hot caramel over the popcorn and 1 cup dry-roasted peanuts salted or unsalted. Working quickly with a large Spatula (lightly sprayed with Cooking Spray to prevent sticking), fold and toss until the popcorn is as evenly coated as possible. Don't worry if it's not perfect — it will spread more in the oven.

Spread the coated popcorn in an even layer on the prepared Baking Sheet(s). Bake at 250°F for 20 minutes, then remove from the Oven and stir/toss the popcorn with the Spatula to redistribute the coating. Return to the Oven and bake for another 5 minutes.

Remove from the Oven and spread the popcorn out on a fresh sheet of Parchment Paper or a clean countertop to cool completely — at least 15–20 minutes. As it cools it will harden into a crispy, crunchy coating. Break apart any large clumps with your hands once it's cool enough to handle.

Once fully cooled and crunchy, serve immediately or store in an Airtight Container or Ziploc Bag at room temperature for up to one week.