Pat chicken wings completely dry with paper towels. Season generously with salt, black pepper, and garlic powder.
Toss wings in cornstarch until evenly coated. Shake off excess.
For deep frying: Heat oil to 350°F. Fry wings in batches for 5–7 minutes until lightly golden. Let rest on a wire rack. Increase oil to 375°F and fry again for 2–3 minutes until deeply golden and crispy.
For air frying: Arrange coated wings in a single layer. Spray with oil. Cook at 400°F for 20–25 minutes, flipping halfway through, until crispy and cooked through.
In a saucepan, combine gochujang, soy sauce, rice vinegar, honey, garlic, ginger, and sesame oil. Whisk over medium heat until sauce bubbles gently and thickens slightly, about 3–4 minutes.
Place hot wings in a large bowl. Pour the hot sauce over the wings and toss until evenly coated.
Transfer to a serving platter and garnish with toasted sesame seeds and green onions. Serve immediately.