Stir together soy sauce, brown sugar, and garlic powder in a saucepan over medium heat. Cook and stir until sugar has dissolved. Remove from heat and allow to cool.
Place chicken wings in a large bowl. Pour soy sauce mixture over wings and toss to coat evenly. Cover the bowl with plastic wrap. Allow chicken to marinate in the refrigerator for 8 hours to overnight.
Preheat the oven to 350 degrees F (175 degrees C).
Pour chicken wings and marinade into a 9x13-inch baking dish. Cover the baking dish with aluminum foil.
Bake in the preheated oven until thoroughly hot, about 45 minutes. Remove foil and bake for 15 more minutes. Serve hot.