Place a piece of parchment on a rimmed baking sheet.
Dry the chicken wings well with paper towels.
Place the wings in a large bowl and add the baking powder, salt and pepper. Toss to combine so there is a light coating all over each wing. Discard any remaining coating.
Place the wings in a single layer on the baking sheet with skin side up. Set in the fridge for 30 minutes.
Preheat oven to 400 degrees F.
Bake for 30 minutes until the wings are golden and crispy. Take out of the oven to cool slightly.
While the chicken wings bake, prepare the sticky Asian sauce. Place all of the sauce ingredients into a saucepan, stir and bring to the boil. Allow to bubble for 5-10 minutes until the sauce reduces and thickens slightly (it will thicken as it cools). Remove from the heat.
Place the wings in a large bowl and very carefully pour over the sticky sauce. Toss to combine. Garnish with green onions sliced on the diagonal.