Pat the drumsticks completely dry with paper towels - this helps the sauce stick and prevents a watery finish. Season all over with salt and pepper. Arrange in a single layer in your slow cooker, meaty side down if they don't all fit flat.

In a large bowl, whisk together ketchup, honey, apple cider vinegar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, and cayenne until completely smooth. The sauce should be pourable but thick enough to coat the back of a spoon.

Pour the sauce evenly over the drumsticks, turning each one to coat all sides. Cover and cook on LOW for 6-7 hours or HIGH for 3-4 hours, until the chicken is fall-off-the-bone tender and registers 165F at the thickest part. Resist the urge to lift the lid during cooking - you'll lose heat and add 15-20 minutes each time.

For sticky, caramelized chicken, transfer the cooked drumsticks to a foil-lined baking sheet. Brush generously with the sauce from the slow cooker and broil 4-5 inches from the heat for 3-4 minutes, watching closely, until the sauce bubbles and just starts to char at the edges.

Let the chicken rest for 5 minutes so the juices redistribute. Serve with the remaining sauce spooned over top, or on the side for dipping. The sauce will be thin - that's intentional for drizzling over rice or potatoes.