Mix the salt, black pepper, and cayenne pepper in a small bowl and rub into both sides of the pork crown roast and refrigerate for three hours or overnight.
Remove the crown from the refrigerator and allow it to come to room temperature.
Heat the pellet grill to 225F.
Place the pork crown in a cast-iron skillet, dust with a little more of the brine mixture, and pour in ½ cup apple juice.
Place the crown roast in the pellet grill and cook until the internal temperature reaches 135F.
Turn up the grill to 450F and give the pork another 15 minutes or so, until the internal temperature reaches 145F.
Remove the cooked crown roast from the pellet grill, cover in foil, and allow to rest for at least 15 minutes.
Serve to a standing ovation.