In a large bowl, whisk together soy sauce, balsamic vinegar, brown sugar, honey, garlic, Sriracha, ginger powder, pepper and onion powder.
Place wings into a slow cooker. Stir in soy sauce mixture and gently toss to combine. Cover and cook on low heat for 3-4 hours or high heat for 1-2 hours.
In a small bowl, whisk together cornstarch and 2 tablespoons water. Stir in mixture into the slow cooker. Cover and cook on high heat for an additional 10-15 minutes, or until the sauce has thickened.
Preheat oven to broil. Line a baking sheet with foil.
Place wings onto the prepared baking sheet and broil for 2-3 minutes, or until caramelized and slightly charred.
Serve immediately with remaining sauce, garnished with sesame seeds and cilantro, if desired.