Gather all dried herbs and spices in a small mixing bowl, checking for freshness.

Measure 3 tablespoons kosher salt, 2 tablespoons freshly ground black pepper, 2 tablespoons garlic powder, 1 tablespoon onion powder, 1 tablespoon dried rosemary, 1 tablespoon dried thyme, and 1 teaspoon smoked paprika into the bowl; add 1/4 teaspoon cayenne pepper if using.

Use a small whisk or spoon to thoroughly combine the rub, breaking up any clumps for even seasoning.

Remove the prime rib from the refrigerator 40 to 60 minutes before cooking and pat the entire surface dry with paper towels.

Lightly coat the roast with olive oil or melted butter, then press the rub mixture onto all surfaces of the meat.

Pay particular attention to the side without the bone or fat cap to ensure a flavorful crust on the visible surface.

Let the seasoned roast rest at room temperature for 15 to 20 minutes (up to 2 hours) before roasting.

Preheat the oven to 450°F (230°C) and roast for 15 minutes; reduce heat to 325°F (165°C) and continue roasting for about 2 hours 15 minutes, or until an instant-read thermometer registers 130°F (54°C) for medium-rare.

Remove the roast and tent loosely with foil; let rest for 15 to 20 minutes before carving.