Preheat the oven to 425°F, line a rimmed baking sheet with foil, and set a wire rack inside it.

Pat the chicken wings completely dry with paper towels.

Toss the wings with the baking powder and kosher salt in a large bowl until evenly coated.

Arrange the wings skin side up on the rack in a single layer with space between each piece.

Bake for 40 to 45 minutes, flipping once at the 20 minute mark, until deep golden and a thermometer reads 165°F in the thickest piece.

While the wings bake, whisk the gochujang, soy sauce, honey, rice vinegar, sesame oil, garlic, and ginger in a small saucepan over medium heat; simmer 3 to 4 minutes, stirring often, until thick and glossy.

Let the baked wings rest for 2 minutes off the heat.

Transfer the wings to a large bowl, pour over the warm sauce, and toss until every piece is coated thick and even.

Pile onto a platter, scatter with sesame seeds and scallion, and serve immediately.