In a large bowl combine the balsamic, soy sauce, honey, garlic, sriracha and ginger and mix well. Add the chicken pieces, toss to completely coat all of the pieces, cover and marinate in the refrigerator for at least 2 hours, or as long as overnight.
Pour half of the marinade (1/4 cup) into a small saucepan. Set aside.
About 20 minutes before cooking, remove the chicken from the refrigerator. About 3 minutes before cooking, preheat the air fryer to 400F. Remove the chicken from marinade and transfer to the air fryer basket. Cook in batches, if necessary, for 14 minutes, turning halfway until cooked through in the center.
Meanwhile, place the remaining sauce in a small pot and cook over medium-low heat until it reduces slightly and thickens, about 1 to 2 minutes. To serve, drizzle the sauce over the chicken and top with scallions.