Set the oven to preheat at 400 F. Rinse and pat dry the chicken legs with paper towels to remove moisture from the skin. Place in a baking dish. Salt the legs and sprinkle with black pepper. Other spices can be used as desired.
Place ketchup in a saucepan, add Worcestershire sauce, apple cider vinegar, water, sugar, paprika. Stir and heat, stirring, until sugar dissolves. Drizzle 3/4 of the sauce over the legs and pour the remaining sauce into a baking dish.
Put pieces of cold butter on top of the legs. Cover the baking dish with foil and place in the preheated oven. Bake for 25 minutes with foil and another 10-12 minutes without foil until they are as browned on the outside as you'd like. (timing will vary depending on how large they are)
If you want to make them REALLY crispy on the outside I suggest switching to broil for the last 2 minutes or so OR throwing them into your air fryer preheated at 400 for a couple of minutes.
Make sure that the legs are baked thru and reach a safe 165 degrees F in the thickest part. Serve them hot, with the remaining BBQ sauce on top.