01 - Pat pork belly thoroughly dry using paper towels. Score pork skin in a crosshatch pattern with a sharp knife, avoiding cutting into the meat beneath.
02 - Rub rice vinegar over pork skin. Sprinkle 1 teaspoon of kosher salt onto the skin only. Flip pork belly and distribute the remaining salt, black pepper, Chinese five-spice powder, and garlic powder evenly over the meat side.
03 - Arrange pork belly skin side up on a wire rack set over a tray. Refrigerate uncovered for a minimum of 2 hours or overnight to desiccate the skin.
04 - Preheat air fryer to 390°F.
05 - Remove pork belly from refrigerator and brush away excess surface salt. Position pork belly skin side up in the air fryer basket.
06 - Air fry at 390°F for 35 to 40 minutes until skin is golden and blistered. For enhanced crispness, increase cooking time by an additional 5 minutes if needed.
07 - Allow pork belly to rest for 10 minutes before slicing. Plate and garnish with sliced scallions to serve.