In a shallow bowl, mix together the flour, garlic powder, smoked paprika, onion powder, black pepper and cayenne pepper (if using). Toss the chicken drumsticks in the flour mixture until they are evenly coated.
Heat the butter or oil in a large skillet over medium-high heat. Add the chicken drumsticks and cook for 8-10 minutes until they are golden brown and crispy.
Remove from the skillet and let cool before serving.