Lay out 4 large sheets of aluminum foil and set aside. Fill hopper of smoker with wood pellets, I usually use hickory, but pecan or cherry would work as well.
Remove membrane from back of ribs. Slide a butter knife into the bone-side of the rack of ribs and make a small slit. Grab the membrane and pull it off. Use a paper towel to get a better grip on it.
Combine mustard, apple juice and Worcestershire sauce. Brush over ribs on both sides. Season ribs with dry rub on both sides. Be generous.
Start smoker on the smoke setting for 5-10 minutes. Increase heat to 225 F degrees. Smoke the ribs, meaty side up, for 3 hours.
Leave smoker on at 225 F degrees and place ribs on foil sheets. Sprinkle rack of ribs on both sides with half of brown sugar and honey, then top with 2 Tbsp of butter. Pour in 3 Tbsp bourbon. Repeat with remaining rack of ribs and remaining brown sugar, honey, butter and bourbon.
Add another foil sheet on top of the ribs and crimp to seal tightly. Return foil packs of ribs to grill and cook for 2 hours.
Carefully remove ribs from foil, and brush ribs with bbq sauce. Place ribs back on grill grate and grill for 1 hour. Slice and enjoy!