In a large mixing bowl, whisk together the buttermilk, ½ cup This Little Goat went to Korea sauce, ½ teaspoon kosher salt and a few grinds of black pepper. \nSeason the chicken on all sides with salt and pepper and add to the bowl containing the buttermilk mixture. Let sit for at least 1 hour, or refrigerated up to overnight.\nIn a shallow bowl or pie pan, combine the flour, 1 ½ teaspoons kosher salt, garlic powder and Korean chili flakes. Mix to combine. \nRemove chicken from the buttermilk mixture, allowing any excess to drip off. Dredge chicken in the flour mixture until well coated on all sides. Transfer to a wire rack and repeat with remaining chicken.\nSpray the basket of an air fryer with non-stick cooking spray. Place the chicken in a single layer in the fryer basket, working in batches if necessary (you don’t want to overcrowd the basket). Cook at 380 degrees for about 15-25 minutes, flipping once halfway through, until the chicken is cooked through to an internal temperature of 165 degrees\nNote: the larger pieces of chicken will take closer to 20-25 minutes, while the smaller pieces will take closer to 15. We recommend cooking similar-sized pieces of chicken together. And, make sure to flip your chicken halfway through to ensure it gets nice and crispy on both sides! \nMeanwhile, whisk the melted butter with remaining ½ cup Korea sauce until well combined and smooth. \nTransfer fried chicken to a serving plate and brush, or drizzle, with buttery Korea sauce. Top with toasted sesame seeds and sliced scallions. Serve warm.