Preheat your oven to 300°F (150°C). Cut the boneless beef short ribs into 4-inch pieces and place them in a 9x13-inch baking dish. Season both sides with kosher salt and black pepper.

In a mixing bowl, whisk together ketchup, dark brown sugar, cider vinegar, Worcestershire sauce, Dijon mustard, chili powder, garlic powder, and cayenne pepper until smooth.

Pour two-thirds of the BBQ sauce over the seasoned ribs, ensuring they are fully coated. Save the remaining sauce for serving later.

Cover the baking dish tightly with foil and bake for approximately 2½ hours.

After 2½ hours, carefully remove the foil and pour off some cooking liquid if overly saucy. Bake uncovered for another 30 minutes to allow the sauce to caramelize.

Once caramelized, transfer the ribs to a serving platter and brush with reserved BBQ sauce. Serve with sides of your choice.