Preheat oven to 400 degrees. Line a baking sheet with parchment paper or foil. If using foil, spray with non stick spray.
In a large bowl, combine wings, oil, butter, garlic powder, and pepper. Toss well to coat completely. Place wings on the prepared pan and bake for 30 minutes—flip wings halfway through cooking.
While the wings are cooking, work on the sauce. In a small saucepan, melt butter. Whisk in corn starch and cook for about 30 seconds. Add other ingredients and bring sauce to a boil. Reduce heat and simmer for 3-4 minutes. Stir until it thickens. Turn off heat and set aside.
After the wings have cooked for 30 minutes, remove the baking sheet from the oven and turn the oven to broil. Carefully drain any juice in the pan. Discard juice. Brush the sauce on the top of the wings covering well, and return the wings to the oven (placing the wings on the middle rack). Broil for 3-4 minutes. Turn wings over, baste again, and broil the other side. Watch carefully so as not to burn the wings.
Remove the pan from the oven. Allow the wings to sit for about 5 minutes before taking a bite. This will allow the sauce to set on the wings.