Remove the membrane from the back of the ribs by sliding a dinner knife under the membrane and over the bone. Lift and loosen the membrane until it tears. Grab the edge of the membrane with a paper towel and pull it off. It might come off in one big piece or you may have to remove it in smaller pieces. This is ESSENTIAL so make sure you take it off.
Mix the rub ingredients in a small bowl.
Spread yellow mustard evenly over the ribs covering completely. Spread the dry rub over the ribs covering completely. Wrap in saran wrap so they are completely covered. Place in fridge to rest a minimum of 2 hours, but we do it overnight for best results!
Prepare your smoker according to manufacture's directions to a heat of 225 degrees Fahrenheit.
Remove the plastic wrap and place ribs, bone side down, on the preheated smoker and let smoke for 3 hours at 225 degrees Fahrenheit.
Mix together 1/2 cup apple juice and 1/2 cup water in a spray bottle and spritz ribs with mixture every half hour.
After 3 hours remove ribs from smoker but leave smoker on at same temperature.
Lay tinfoil out on counter and lay the ribs on the foil. Mix 1/2 cup BBQ sauce and 1/2 cup apple juice together in small bowl. Pour it carefully over the ribs and seal up the foil so nothing leaks out. Place ribs back in the smoker at 225 degrees Fahrenheit for another 2 hours.
Remove the ribs from the smoker after 2 hours. Remove the ribs from foil. Mix together BBQ sauce and brown sugar for the finishing sauce in a mixing bowl. Coat ribs with finishing sauce and place back on the smoker, unwrapped for 1 hour.
Remove from smoker and brush with remaining sauce and serve.