Combine marinade ingredients and chicken drumsticks in a zip lock bag or a large bowl.
Mix well and ensure chicken is well coated, cover (if using a bowl) and marinate for 1 hour or overnight. (note 1)
Bring marinated chicken up to room temperature before moving onto the next step. Take the chicken out of the fridge 30 minutes before cooking will do the trick.
Preheat oven to 200°C/400°F.
With a pair of tongs, place chicken drumsticks onto a lined baking tray. Reserve and set aside the marinating liquids. You'll need it later.
Place the tray of chicken onto the middle rack of the oven and bake for 35 minutes.
Take the chicken out of the oven, flip drumsticks over and pour the reserved marinade all over the drumsticks. Pop the tray back into the oven and change the oven setting to grill/broil. Grill/broil for 7 minutes.
Take the chicken out of the oven, flip drumsticks over, brush marinade over the chicken and return onto the top rack of the oven. Grill/broil for a further 7 minutes.
To serve, transfer drumsticks onto a serving dish, drizzle sauce over the chicken and sprinkle sesame seeds and spring onions/scallions.