In a large glass bowl, combine the baking powder, salt, and black pepper.
Add the chicken wings to the bowl and toss to coat evenly.
Spray the air fryer basket with cooking spray and arrange the wings in a single layer in the basket.
Set Air fry the wings at 375 degrees F for 15 minutes, flipping them halfway through, until they're lightly golden brown and crispy.
While the wings are cooking, make the teriyaki sauce. In a small saucepan over medium heat, combine the soy sauce, brown sugar, rice wine vinegar, water, sesame oil, garlic, and ginger (if using). Bring the mixture to a boil, then reduce the heat and simmer for 3-4 minutes, until it thickens slightly.
Add the cornstarch mixture to the sauce and stir to combine. Cook for an additional 1-2 minutes, until the sauce thickens to your liking.
When the wings have cooked for 15 minutes, transfer them to a large bowl with half the sauce (reserve the other half for later) and toss with the teriyaki sauce until coated evenly.
Add them back to the air fryer for an additional 5 minutes. If you want to add a nice char, Broil them at 400 degrees F for 5 minutes more.
Remove the wings from the air fryer basket, brush on the remaining sauce. Sprinkle the sesame seeds and green onions over the wings and serve the wings on a serving platter with your favorite sauces for dipping.
