Add rub ingredients to a gallon sealable bag.
Next, add chicken drumsticks and shake to coat.
Then, set drumsticks in slow cooker.
Pour chicken broth or orange juice to the bottom of slow cooker.
Mix prepared barbecue sauce, orange marmalade, orange zest, 2 T. orange juice and chili powder together. Drizzle half a cup of sauce over drumsticks, reserve remaining sauce for later.
Cook in slow cooker on high for 4 hours.
Preheat oven to broiler, I leave my rack about 6 inches from the broiler element.
Line a baking sheet with aluminum foil, spray with non-stick baking spray. Remove drumsticks from slow cooker and lay on baking sheet.
Baste drumsticks with sauce.
Broil for 3-5 minutes. Remove from oven, baste again, and broil for 3-5 more minutes.
Serve immediately! I like to save a little extra sauce for dunking!