Prepare the Marinade: In a mixing bowl, combine the soy sauce, honey, rice vinegar, minced garlic, grated ginger, sesame oil, black pepper, and red pepper flakes (if using). Whisk until well blended.
Marinate the Drumsticks: Place the chicken drumsticks in a large resealable plastic bag or a bowl. Pour the marinade over the drumsticks, ensuring they are evenly coated. Seal the bag or cover the bowl, then refrigerate for at least 1 hour, preferably overnight for maximum flavor.
Preheat the Oven: When ready to cook, preheat your oven to 400°F (200°C).
Arrange the Drumsticks: Line a baking sheet with aluminum foil for easy cleanup. Place a wire rack on top of the baking sheet (if you have one). Arrange the marinated drumsticks on the rack, allowing excess marinade to drip off.
Bake: Bake in the preheated oven for 30-35 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (75°C). For extra caramelization, broil for the last 2-3 minutes, keeping an eye to prevent burning.
Garnish and Serve: Once done, remove from the oven and let rest for a few minutes. Garnish with chopped green onions and a sprinkle of sesame seeds before serving.