In a small bowl, stir together the 1 tablespoon Diamond kosher salt, 1 tablespoon light brown sugar, 1 tablespoon paprika, ½ to 1 tablespoon red pepper flakes, 1 tablespoon ground cumin, and 1 tablespoon coarsely ground black pepper.
Rub the one (6 ½- to 8-pound) bone-in skinless pork butt all over with the spice mixture. The pork butt should be completely coated on all sides.
If you have time, tightly wrap the pork in plastic wrap, place it on a plate, and refrigerate overnight (8 to 12 hours) to let the flavors 'hold hands.'
Crank the oven temperature to 250°F (121°C). Place a roasting rack in a large pan.
Place the pork butt, fat cap side up, on the rack. Roast the pork, uncovered, until the internal temperature reaches 195°F to 205°F (90°C to 96°C).
Remove the pork from the oven and let the roast rest for 30 minutes on a cutting board.
Shred the roast pork butt with a couple of forks, evenly mixing the crisp, dry edges with the insanely moist, tender pork inside.
