Combine 1 cup water, soy sauce, brown sugar, honey, ginger, and garlic powder in saucepan over medium heat. Cook until nearly heated through, about 1 minute.

Meanwhile, mix cornstarch with 1/4 cup cold water in a separate vessel. Stir until dissolved. Stir again just before adding to the saucepan, then cook and stir sauce until thickened, 5-7 minutes.