Pat the wings very dry with paper towels.
Toss the wings with 1 teaspoon kosher salt and ½ teaspoon white pepper. Add the cornstarch and baking powder and toss until evenly and thinly coated. Shake off any excess.
Preheat the air fryer to 380°F. Arrange the wings in a single layer, working in batches if needed, and spray lightly with oil.
Air fry for 20 minutes, flipping halfway through and spraying any dry spots with oil.
Increase the heat to 400°F and air fry 5 to 7 minutes more, until deep golden and the thickest piece reads at least 165°F (175°F to 185°F for the best texture).
Meanwhile, stir together the finishing salt ingredients in a small bowl.
Heat 1 tablespoon oil in a large skillet or wok over medium heat. Add the garlic, chilies, and scallion whites and stir for 45 to 60 seconds, until fragrant.
Add the wings, about half of the finishing salt, and the sesame oil. Toss for 30 seconds. Taste and add more finishing salt if desired.
Top with the scallion greens and serve immediately.