Pat the chicken wings very dry with paper towels. For maximum crispness, arrange them uncovered on a wire rack in the refrigerator for at least 30 minutes or overnight.

Heat the oven to 425°F (220°C). Line a rimmed baking sheet with foil, place a wire rack over it, and lightly grease the rack.

Combine the baking powder, kosher salt, and black pepper in a small bowl. Toss the wings thoroughly with this mixture so every piece has a light, even coating.

Arrange the wings in a single layer with space between each piece. Bake for 20–25 minutes, turn the wings, and bake for another 20–25 minutes until deeply browned and crisp; the thickest pieces must reach at least 165°F (74°C), though 175–185°F often gives wings a more tender texture.

While the wings bake, combine the orange juice, orange zest, soy sauce, honey or brown sugar, rice vinegar, garlic, ginger, and sesame oil in a saucepan. Bring the mixture to a simmer and reduce it for about 5–7 minutes.

Stir the cornstarch and cold water together until smooth. Whisk the slurry into the simmering sauce and cook for 1–2 minutes, until the glaze is glossy and thick enough to coat a spoon.

Toss the hot, crisp wings with only enough sauce to coat them. Finish with green onions, sesame seeds, orange zest, or red-pepper flakes, and serve immediately.