In a large plastic bag, put in the orange juice, lemon juice, hoisin sauce, sugar, oil, ginger and garlic. Seal and shake to mix. Add wings, seal and shake to coat evenly. Refrigerate overnight or up to 3 days. When going to bake wings, put extra sauce in a small saucepan. Heat to medium. Mix cornstarch and cold water in a small bowl. Slowly add cornstarch mix to sauce to thicken. Bring to a boil, whisking constantly, and then turn down to simmer.

Preheat oven to 400°. Line a large baking sheet pan with aluminum foil. Spray with cooking spray. Spread the wings on the foil and bake for 20 minutes; flip the wings over and brush with the thickened sauce. Continue to bake for 25 minutes so wings are cooked and golden brown. Transfer to a serving platter and sprinkle with scallions.