1Set oven control to broil. Spray 3 1/2- to 4-quart slow cooker with cooking spray. Spray broiler pan rack with cooking spray. Sprinkle drummettes with salt and pepper. Place on rack in pan.
2Broil 3 inches from heat 8 minutes or until browned. Place drummettes in slow cooker. In small bowl, mix barbecue sauce, Sriracha sauce, soy sauce and garlic; pour over drummettes.
3Cover; cook on Low heat setting 3 hours. Serve with sauce for dipping. Garnish with sesame seed and onions.