Preheat your smoker to 250°F.
Flip your pork butt with the fat cap facing up. Score the fat cap with your knife in a crisscross pattern.
Coat the pork butt in yellow mustard.
Season generously with a Pork BBQ Rub.
Let the pork butt rest at room temperature for 20 to 30 minutes, or until the meat starts to sweat and the rub looks moist.
Place the pork butt directly on the grates of your smoker with the fat cap facing down.
After about 90 minutes, grab a spray bottle filled with apple juice and spritz the entire exterior of your pork butt.
Continue to spritz every 60 to 90 minutes for about 6 hours, or until the internal temperature reaches between 165°F and 175°F.
Grab a disposable aluminum pan and transfer your pork butt into the pan.
Pour 1 cup of apple juice into the bottom of the pan.
Lay 6 x 1 tbsp pats of butter down on the top of your pork butt.
Sprinkle the remaining 2 tbsp of Pork BBQ Rub on the top of the pork butt.
Sprinkle ½ cup of light brown sugar over the top of the pork butt.
Wrap the entire pork butt in aluminum foil and place back on the smoker, still at 250°F.
Let it smoke for another 5 to 6 hours, or until the internal temperature is between 200°F and 205°F.
Remove the pan from the smoker, but leave the foil intact. Transfer the pan to a Cambro Go Box or insulated cooler and allow the pork butt to rest for at least 30 minutes (or up to 4 hours).
Shred the butt into pulled pork and enjoy!