In a bowl, soak the chicken pieces in buttermilk for at least 30 minutes (or up to 2 hours) in the refrigerator.
In a separate bowl, combine the flour, cornstarch, baking powder, garlic powder, ginger powder, salt, and pepper. Mix thoroughly.
In a deep skillet or wok, heat about 2 inches of oil over medium-high heat until shimmering (around 350°F / 175°C).
Remove the chicken from the buttermilk, allowing excess to drip off. Dredge each piece in the flour mixture, pressing lightly to ensure an even coating.
Carefully place the coated chicken pieces in the hot oil, working in batches to avoid overcrowding. Fry for about 4-5 minutes or until golden brown and crispy. Use a slotted spoon to transfer cooked chicken to a paper towel-lined plate to drain excess oil.
In a small saucepan, combine honey, soy sauce, rice vinegar, and sesame oil. Cook over low heat, stirring until well combined and heated through (about 3-5 minutes).
In a large mixing bowl, add the fried chicken and drizzle the honey sauce over it. Toss gently until the chicken is well coated.
Sprinkle the toasted sesame seeds on top of the chicken and garnish with sliced green onions.
Notes
Serve on a large platter with extra honey sauce and garnish for an appetizing look.