Preheat the oven to 300 degrees F (150 degrees C).
Cut the Boneless Beef Short Ribs (4 pound) into 4-inch long pieces. Season the ribs all over with Kosher Salt (2 teaspoon) and Ground Black Pepper (1 teaspoon), then arrange in a 13 by 9-inch baking dish.
Combine Ketchup (1 cup), Dark Brown Sugar (3/4 cup), Apple Cider Vinegar (1 1/2 tablespoon), Worcestershire Sauce (1 1/2 tablespoon), Dijon Mustard (1 1/2 tablespoon), Chili Powder (1 1/2 tablespoon), Garlic Powder (3/4 teaspoon), and Cayenne Pepper (1/4 teaspoon) in a small bowl and stir until smooth.
Pour one-third of the sauce over the short ribs. Using tongs, flip the ribs over and spoon another one-third of the sauce over top. Reserve the remaining BBQ sauce to spoon over the cooked ribs.
Cover the pan with aluminum foil and roast for 2 and a half hours.
Remove the foil and, if the cooking liquid is covering the meat, use a large spoon or ladle to remove some of the liquid so that the tops are exposed.
Cook for 30 minutes more, uncovered, until the meat is tender and browned. Cut off any excess fat that remains around the short ribs. Transfer the short ribs to a serving platter. Discard the cooking liquid, as it will be very greasy.
Slather the reserved BBQ sauce over the short ribs. Serve and enjoy!