Place chicken drumsticks in a large, lightly greased casserole dish. Whisk together all remaining ingredients.
Pour marinade on top of chicken. Cover casserole dish and marinate in fridge for at least 6 hours or overnight.
Preheat oven to 400°F. Remove casserole dish from fridge while oven is preheating.
Roast for 60 minutes, or until thickest part of drumstick meat reads 165°F on meat thermometer and chicken is deep brown in places. If needed, broil for about 5 minutes to obtain more colour.
Remove chicken from oven and let rest for 10 minutes. Garnish with parsley, if desired.