Preheat smoker to 225 degrees
Trim the pork butt well, removing all the extra fat from the outside. (See video tutorial for details!)
Mix 50/50 Yellow Mustard and Molasses
Coat top and sides of pork butt with mustard / molasses binder
Generously sprinkle on Bad Byron's Rub all over
Flip pork butt and repeat for the other side
Allow rubbed and seasoned pork butt to "setup" at least 30 minutes (on a wire cookie cooling rack if available)
Put seasoned pork butt on the smoker for 6 to 7 hours, until internal temperature reaches approximately 165 degrees
Move pork butt into pyrex dish (if finishing in the oven) or a large foil pan
Add slides of butter to the top, BBQ sauce, and sprinkle generously with brown sugar
Wrap well with foil
Cook another 7 to 8 hours until internal temperature hits 205 degrees (Continue cooking at 225 degrees, either in the oven or on the smoker)
Allow pork butt to REST at least an hour, preferably at least 3
Pull out the bone and pull the pork! Enjoy!