In a large mixing bowl, combine the soy sauce, rice vinegar, sesame oil, grated ginger, minced garlic, brown sugar, and gochujang. Mix well until the sugar is dissolved.

Add the chicken wings or drumsticks to the marinade and toss until they are well coated. Cover the bowl and let it marinate in the refrigerator for at least 1 hour.

In a separate bowl, combine the all-purpose flour, cornstarch, baking powder, and salt. Mix well.

Heat vegetable oil in a deep frying pan or pot to 180°C (350°F).

Remove the chicken from the marinade, allowing any excess marinade to drip off. Coat each piece of chicken in the flour mixture, shaking off any excess.

Carefully place the coated chicken into the hot oil, frying in batches to avoid overcrowding the pan. Fry for about 8-10 minutes or until the chicken is golden brown and crispy. Remove the chicken from the oil and let it drain on a paper towel-lined plate.

Repeat the frying process until all the chicken is cooked.

Garnish the Korean Fried Chicken with sesame seeds and chopped spring onions (if desired).

Serve the Korean Fried Chicken hot as an appetizer or with steamed rice and pickled vegetables as a main dish.