Place the pancetta in a cold, large, heavy-bottomed soup pot. Bring to medium heat and slowly cook the pancetta, stirring occasionally and making sure it does not burn, until very crispy. Remove the pancetta with a slotted spoon and set aside to drain on paper towels, reserving the fat in the pot.
Add 3 test kernels to the pot and cover. Once they pop, add the rest of the kernels and partially cover to let out steam. Once the kernels start popping aggressively, shake the pot to keep things moving. Once the popping frequency slows down, take the pot off the heat.
Blend 1 tablespoon salt and the brown sugar in a mini food processor to create a popcorn dust. Add the melted butter to the popcorn and stir, then add the pancetta, cheese and a couple pinches of the popcorn dust to taste. Shake vigorously to mix.