Gochujang Butter Grilled Wings

Name: Gochujang Butter Grilled Wings
Ingredients: 3 pounds chicken wings, preferably party wings; 2 teaspoons baking powder; 2 teaspoons cornstarch; 1 teaspoon kosher salt; 2 cloves garlic; 1 (1-inch) piece ginger; 2 tablespoons unsalted butter; 1/4 cup honey; 2 tablespoons gochujang (Korean chile paste); 2 tablespoons soy sauce or tamari; 1 tablespoon plus 1 1/2 teaspoons rice vinegar; 1 teaspoon toasted sesame oil; 1 medium scallion, thinly sliced (optional); White sesame seeds, for garnish (optional)