- Make the rub: Combine ingredients in a bowl and use a whisk or your fingers to incorporate. Store leftovers in a sealed jar.
- Make the sauce: Whisk together ingredients and season to taste; add more Worcestershire and hot sauce as desired.
- Prep your grill or smoker for direct heat. Build it hot and burn down to coals, then spread them out to make a bed of hot coals. Meanwhile, in a large bowl combine 1⁄2 cup of the rub with the brown sugar, garlic powder, cinnamon, onion powder, cayenne, mustard sauce, beer, and 2 quarts of water.
- Put both racks of ribs meat side down in a large disposable roasting pan and pour the mixture over them. Cover with foil, securing it tightly around the pan's edges to create a good seal. Place over the hot coals and let the ribs and sauce simmer for a little over an hour, or until you can bend the rack without the meat breaking away or falling off the bone.
- Remove the racks to a clean pan. Add more wood to the fire. Transfer the sauce to a saucepan, then allow it to cool so that you can skim the fat from the top. Bring to a boil and cook until it has reduced to about 3 cups, for about half an hour. Off the heat, stir in the molasses and butter. Set aside.
- To finish the ribs, move the coals to one side of the grill. Sprinkle the remaining 1⁄2 cup rub on both sides of the racks, then lay them on the grate opposite the fire with the thick ends closer to the heat. Smoke gently at about 225 degrees for about 11⁄2 hours, until the ribs are fork tender, watching the fire closely to make sure the temperature does not get too hot and burn the meat.
- Transfer the ribs to a clean tray or cutting board and allow them to rest, tented loosely with foil, for about 15 minutes. Dust with a little more of the rub, cut the ribs apart, and serve with the warm sauce. Serves 4