Whisk together brown sugar, soy sauce, ginger, dry mustard and garlic powder.
Place wings in a large (gallon size) zip lock bag and pour marinade over them. Seal the bag and refrigerate overnight or up to 48 hours. Turn once or twice to distribute marinade.
Place chicken on foil lined (nonstick foil works well) sheet pan and bake for 25 minutes. Remove pan from oven, turn wings over and continue baking another 25 minutes. Sprinkle with sesame seeds (if using) and enjoy!