- Heat the oven to 250°F (120°C) with racks in the lower-middle and upper-middle positions. Line a rimmed sheet with foil and set a wire rack on it.
- Pat the wings very dry. Toss with the baking powder and salt and spread on the rack without touching.
- Bake on the lower-middle rack for 30 minutes to render the fat.
- Move the pan to the upper-middle rack, raise the oven to 425°F (220°C) and bake until deep golden and crisp, 40 to 50 minutes.
- Meanwhile, melt the butter with the hot sauce and garlic powder in a small pan.
- Toss the hot wings in the sauce and serve right away with celery and blue cheese dressing.