Prepare the Chicken:
In a bowl, mix cornstarch, flour, baking powder, salt, pepper, and five spice.
In a separate bowl, whisk the egg with buttermilk.
Dip the chicken into the buttermilk mixture, then coat evenly in the dry mix.
Cooking Methods:
Deep-Frying: Heat oil to 350°F (175°C). Fry chicken in batches for 5-6 minutes until golden and crispy. Drain on a wire rack.
Air-Frying: Preheat air fryer to 400°F (200°C). Spray chicken with oil and cook for 10 minutes, flipping halfway.
Baking: Preheat oven to 425°F (220°C). Place coated chicken on a wire rack over a baking sheet. Spray with oil and bake for 20-25 minutes.
Make the Sauce:
In a pan over medium heat, combine sweet chilli sauce, soy sauce, honey, garlic, red pepper flakes, vinegar, sesame oil, and ginger.
Mix cornstarch with water and stir into the sauce to thicken.
Simmer for 2 minutes, stirring constantly.
Combine:
Toss crispy chicken pieces in the sauce until well coated.
Serve immediately, garnished with sesame seeds and chopped green onions.