Whisk cornstarch, soy sauce, oil, flour, sugar, eggs, sesame seeds, salt, and garlic powder together in a bowl. Pour marinade into a resealable plastic bag. Add chicken, coat with the marinade, squeeze out excess air, and seal the bag. Marinate in the refrigerator, 5 hours to overnight.
Preheat oven to 350 degrees F (175 degrees C). Line a rimmed baking sheet with aluminum foil.
Remove chicken from marinade and transfer to the prepared baking sheet. Discard unused marinade.
Bake in the preheated oven until no longer pink at the bone and the juices run clear, about 30 minutes. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).