In a large bowl, whisk together soy sauce, vinegar, Worcestershire sauce, brown sugar, honey, minced garlic, Sriracha, ground ginger, pepper, garlic powder and onion powder.
Place drumsticks into your slow cooker.
Pour sauce over the drumsticks and toss to combine.
Cover and cook on low heat for 6 hours (or high heat for 3-4 hours). Use a slotted spoon or tongs to turn your drumsticks over in the sauce every few hours to make sure all sides are coated in the sauce.
In a small bowl, whisk together cornstarch and 2 tablespoons water. Pour this slurry into your slow cooker and stir gently.
Cover and turn the heat up to high for an additional 10-15 minutes, or until the sauce has thickened.
Serve immediately, garnished with sesame seeds if desired.