Combine chicken pieces with soy sauce and cornstarch in a bowl. Let marinate for 15-20 minutes.
Preheat the air fryer to 375°F (190°C). Place the marinated chicken in the basket, spray with cooking spray, and air fry for 8-10 minutes, shaking the basket halfway through.
In a bowl, whisk together soy sauce, hoisin sauce, sherry wine (or chicken broth), sugar, cornstarch, sesame oil, red pepper flakes, and ground ginger.
Cook spaghetti according to the package instructions until al dente. Drain and set aside.
In a large skillet or wok, heat vegetable oil over medium-high heat. Add garlic, green onions, and red bell pepper. Sauté for 2-3 minutes.
Pour the prepared sauce into the skillet and bring to a simmer until it thickens.
Stir in the air-fried chicken and peanuts to the sauce, mixing to combine and heat through.
Toss the cooked spaghetti into the skillet, ensuring it’s evenly coated with the sauce and chicken.
Garnish with extra green onions or sesame seeds, if desired, and serve hot.