Day 1: Prepare the Pork Belly. Score the skin of the pork belly using a sharp knife or a specialized scoring tool, being careful not to cut into the meat. Pat the pork belly extremely dry with paper towels. Rub 1-2 tablespoons of coarse sea salt all over the skin and meat, ensuring it gets into the scores. Place the pork belly, skin-side up, on a wire rack over a baking sheet. Refrigerate uncovered overnight (at least 12 hours) to air dry the skin.

Day 2: Preheat Air Fryer. The next day, remove the pork belly from the refrigerator. Pat the skin completely dry again with paper towels to remove any moisture. Preheat your air fryer to 400°F (200°C).

Season and Air Fry - First Side. Brush the skin of the pork belly generously with white vinegar. Sprinkle an additional 2 teaspoons of coarse sea salt evenly over the skin. If desired, lightly season the meat side with black pepper and garlic powder. Carefully place the pork belly, skin-side up, in the air fryer basket. Air fry at 400°F (200°C) for 25 minutes.

Air Fry - Second Side. Carefully flip the pork belly over so it's meat-side up (skin down). Continue to air fry at 400°F (200°C) for another 25 minutes, or until the meat is cooked through and tender.

Rest and Serve. Remove the pork belly from the air fryer and let it rest for 10-15 minutes before slicing. This allows the juices to redistribute, ensuring a more tender and flavorful result. Slice against the grain into desired portions and serve immediately.