Heat the oven to 425°F with a rack in the upper-middle position. Set a wire rack over a foil-lined rimmed sheet pan.
Blot the wings thoroughly. Toss with baking powder and salt until no white clumps remain.
Arrange skin-side up and roast 25 minutes. Turn and roast 18 to 25 minutes more until browned and at least 165°F in several thick pieces.
While the wings finish, whisk gochujang, honey, soy sauce, vinegar, sesame oil, garlic and ginger in a small pan. Simmer gently for 2 minutes, stirring.
Rest the wings 5 minutes. Toss with enough warm glaze to coat; reserve excess rather than saturating the skin.
Transfer to a platter and sprinkle with sesame seeds and scallions. Serve immediately.