Place drumsticks in the bottom of the slow cooker.
In a small bowl, mix together brown sugar, salt, black pepper, smoked paprika, garlic powder, and onion powder. Sprinkle on top of chicken. Pour 1 cup of BBQ sauce on top of the chicken.
Place the lid on top of the slow cooker and cook on LOW heat for 5-6 hours or HIGH heat for 2-3 hours.
Remove the drumsticks and place on a large rimmed baking sheet (line it with aluminum foil for easy clean up) in a single layer.
Preheat the broiler on your oven.
Brush the drumsticks with the remaining BBQ sauce and broil the chicken until lightly browned (about 2-3 minutes - watch carefully so that it doesn’t burn while broiling!).
Notes
Keep a close eye on the chicken when broiling, they crisp up quickly!