Prep: Flip the ribs, so that the bones are facing up. Using a paper towel, pull off the membrane and discard. Trim off the flap of meat on the backside. Trim and remove any excess fat.
Season: Rub the backside with mustard and pork rub. Let rest in the fridge for 15 minutes. Flip and rub the topside with mustard and pork rub. Let rest in the fridge while you heat your grill to 300F degrees with an indirect heat zone.
Grill: Place the ribs on the grill over indirect heat meat side up. Smoke with the lid closed for 1 hour and 15 minutes. At the 30-minute and one-hour marks, spritz with apple cider vinegar.
Wrap: Place two sheets of heavy-duty aluminum foil on the counter. Top with 4-5 pats of butter, 1-2 tablespoons brown sugar, a liberal drizzle of honey and 2 tablespoons juice or mop sauce. Place the ribs on the butter, meat side down. To the bone side of the ribs, add 4-5 more pats butter, 1-2 more tablespoons brown sugar and another drizzle of honey. Wrap tightly, crimping up the ends.
Braise: Place back on the smoker for 45 minutes to one hour. The ribs should bend when you pick them up.
Final Step: Remove from the smoker and unwrap from the foil. Flip the ribs over. Brush with sauce. Return to the smoker for 10-15 more minutes to set the sauce. Remove from the smoker. Let rest a few minutes and slice.
Nutritional content will vary, depending on how much mustard, sugar, honey and BBQ sauce you use.