For the wings: Preheat the oven to 400 degrees F. Coat a baking sheet with nonstick cooking spray.
Use a paper towel to pat the chicken wings dry. Sprinkle both sides of the wings with salt and pepper.
Combine the flour, baking powder, chili powder, garlic powder, onion powder, paprika, 1 teaspoon salt and 1 teaspoon pepper in a large bowl. Add wings to the mixture and toss to coat. Shake the wings to remove any excess mixture and place on the prepared baking sheet. Drizzle with the melted butter.
Bake, flipping halfway through, until browned and crispy, about 45 minutes.
For the miso dip: Whisk together the sour cream, miso soup mix, chives, garlic powder, onion powder and some pepper in a small bowl until combined.