Preheat oven to 250°F. Prepare a baking sheet with foil and a rack and spray with non-stick spray. Dry the chicken wings completely with paper towels.
Combine the baking powder, salt, and pepper in a large bowl. Add the dry chicken wings to the bowl and shake to fully coat (you can also use your hands to ensure each piece is fully coated). Tap off the excess coating and place the wings on the prepared baking sheet.
Place the baking sheet on the lower rack in the oven and cook for 3o minutes at 250°F.
After 30 minutes, turn up the heat to 425°F. Carefully move the oven rack to the top setting and place the baking sheet back in the oven. Continue to bake the wings for additional 45-50 minutes. Rotate the pan halfway through the cooking time. The wings will be lightly browned when done. Be careful when rotating the pan and removing the wings when finished baking because the drippings are hot
While the wings are cooking at the higher temp, add all of the sauce ingredients to a medium saucepan and stir to combine. Cook over medium-high heat until boiling. Lower the heat and simmer for 5-7 minutes. Remove the sauce from the heat and pour it into a large bowl.
Once the wings have finished baking, remove the pan from the oven and allow the wings to cool slightly. Add the wings to the bowl of sauce and use tongs to toss and fully coat each wing with sauce (be careful the wings are still hot!).
Place the wings on a serving plate. Pour the remaining sauce over the wings and sprinkle with the chopped green onion and sesame seeds. Enjoy!