Step 1: Prepare the Chicken

1. Cut chicken thighs into uniform 1-inch pieces for even cooking.
2. Place chicken in a bowl with buttermilk and marinate for 15 minutes.
3. In a large bowl, whisk together flour, cornstarch, garlic powder, onion powder, paprika, salt, and pepper.
4. Set up coating station with flour mixture and beaten eggs in separate shallow dishes.

Step 2: Create the Double Coating

1. Remove chicken from buttermilk and dredge each piece in flour mixture, shaking off excess.
2. Dip coated chicken into beaten eggs, ensuring complete coverage.
3. Return to flour mixture for second coating, pressing gently to adhere.
4. Place double-coated chicken on a wire rack and let rest for 5 minutes.

Step 3: Fry the Chicken

1. Heat vegetable oil to 350°F (175°C) in a large, heavy-bottomed pot.
2. Fry chicken in batches of 8-10 pieces to avoid overcrowding.
3. Cook for 4-5 minutes until golden brown and internal temperature reaches 165°F (74°C).
4. Transfer to paper towel-lined plate to drain excess oil.

Step 4: Make the Sesame Glaze

1. In a small saucepan, whisk together soy sauce, honey, rice vinegar, sesame oil, garlic, and ginger.
2. Bring mixture to a simmer over medium heat.
3. In a small bowl, whisk cornstarch with water until smooth to create slurry.
4. Add cornstarch slurry to simmering sauce, whisking constantly.
5. Cook for 1-2 minutes until glaze thickens and coats the back of a spoon.
6. Remove from heat and stir in red pepper flakes if using.

Step 5: Combine and Serve

1. In a large bowl, toss hot crispy chicken with warm sesame glaze until evenly coated.
2. Transfer to serving platter and garnish with toasted sesame seeds and sliced green onions.
3. Serve immediately over steamed jasmine rice.