Adjust the oven rack to the middle position and preheat the oven to 450°F (218°C). Line a large baking sheet with foil and set a wire rack inside, coating it with vegetable oil. Thoroughly dry the chicken wings between paper towels.
In a large bowl, whisk together the baking powder, salt, and pepper. Add the wings to the bowl and coat them evenly with the baking powder mixture. Space the wings evenly on the wire rack. Bake for 20 minutes, then flip and bake for another 15 minutes. Flip again and bake until the skin is golden brown and crisp, about 15 minutes. Remove the wings from the oven and set aside.
In a medium-sized saucepan, whisk together the soy sauce, 3/4 cup water, honey, rice vinegar, mirin, sesame oil, ginger, and garlic. Bring the sauce to a boil over medium-high heat and cook for 1 minute. Meanwhile, in a small bowl, whisk together the cornstarch and 2 tablespoons of water. Add the cornstarch slurry to the boiling sauce and whisk to combine. Continuously stir until the sauce thickens and coats the back of a spoon, about 30 to 60 seconds.
Toss the wings in enough teriyaki sauce to coat, or serve the sauce on the side for dipping. Serve immediately.