Stir the soy sauce, brown sugar, and garlic powder together in a saucepan over medium heat; cook and stir until the sugar melts completely. Remove from heat and allow to cool.
Place the chicken wings in a large bowl. Pour the soy sauce mixture over the wings and toss to coat evenly. Cover the bowl with plastic wrap. Allow chicken to marinate in refrigerator overnight or 8 hours.
Preheat an oven to 350 degrees F (175 degrees C).
Pour the chicken wings and marinade into a 9×13-inch baking dish. Cover the baking dish with aluminum foil.
Bake in the preheated oven until thoroughly hot, about 45 minutes. Remove the aluminum foil from the baking dish and continue baking uncovered another 15 minutes. Serve hot.