In a large bowl, combine flour, cornstarch, baking powder, salt, black pepper, garlic powder, onion powder, and cayenne pepper.

In another bowl, pour the buttermilk over the chicken wings, ensuring they are well-coated. Let the chicken marinate for at least 30 minutes, or up to 2 hours in the refrigerator.

Heat about 2 inches of vegetable oil in a large, deep skillet or pot over medium-high heat until it reaches 350°F.

Remove the chicken from the buttermilk and let excess drip off. Dredge each wing in the flour mixture, ensuring they are evenly coated.

Carefully place the coated wings in the hot oil, frying in batches to avoid overcrowding. Fry for about 8-10 minutes, or until golden brown and crispy.

Use a slotted spoon to transfer the wings to a paper towel-lined plate to drain excess oil.

In a small saucepan, combine gochujang, honey, soy sauce, rice vinegar, sesame oil, minced garlic, and grated ginger. Cook over medium heat, stirring until the sauce is well combined and heated through, about 3-5 minutes.

Toss the fried chicken wings in the sauce until they are fully coated. Sprinkle with sesame seeds and garnish with sliced green onions before serving.