In a mixing bowl or bag, combine balsamic vinegar, honey, brown sugar, soy sauce, and garlic powder. Add the chicken and toss to coat. Refrigerate for 2 hours.
Place drumsticks on a baking sheet and set the additional sauce aside. Bake on a baking sheet at 425 degrees F for about 30-45 minutes or until cooked through.
Meanwhile, pour sauce in a small pot and bring to a boil. Reduce the heat and simmer for about 10-15 minutes or until slightly thickened.
Allow sauce and drumsticks to cool and then place in an airtight container (Sauce should be placed in a separate bag), label, and freeze for up to 3 months.
When ready to cook, remove sauce bag and allow to thaw. Place drumsticks on a baking sheet and bake at 425 degrees for 45 minutes, flipping halfway through, then top with sauce and cook for an additional 10-15 minutes or until chicken is cooked to 165 degrees F. Serve and enjoy!