Pat the meat dry with paper towels. Blend coffee, brown sugar, bourbon, 2 teaspoons salt, and the peppers. Rub all over and into meaty parts of roast. If you're making a bone-in roast, set bone side down on a rimmed baking sheet. For boneless roast, it doesn't matter which side is down. Chill, uncovered, at least 1 and up to 2 days.
Roasting:
Preheat oven to 450°F. Sprinkle all over with remaining 1 teaspoon of salt.
Place shallots beneath V-shaped rack in a roasting pan. Set roast, bone side down (if making bone-in roast), on rack. Roast for 30 minutes, then reduce temperature to 350°F and roast another 30 minutes.
Remove shallots with tongs and let cool. Keep roasting beef until an instant-read thermometer inserted into center of thickest part reaches 125° -130°F for medium-rare, 1 to 1 3/4 hours longer.On average, it takes about 12 minutes per pound to cook a boneless rib roast to medium-rare. A bone-in roast typically takes 15 minutes per pound.
Lift to a cutting board and let rest 30 to 40 minutes, loosely tented with foil.
Gravy:
Squeeze soft insides of roasted shallots into a blender. Add broth, cream, bourbon, and coffee and whirl until smooth.
Set roasting pan on stovetop and pour gravy into pan. Cook over medium-high heat, scraping up browned bits, until gravy thickens slightly and turns a nutty brown, 2 to 3 minutes. Season with salt and strain into a serving bowl.
Slice rib roast meat 1/3 to 1/2 inches thick and if applicable, cut between bones. Serve with gravy.
Notes
If you'd like to make this recipe using a bone-in prime rib roast, it will require a longer cook time. On average, it takes about 12 minutes per pound to cook boneless prime rib to medium-rare. A bone-in roast typically takes 15 minutes per pound. Or, ask your butcher to remove the bones and then tie them back onto the roast for you. Then you can make it according to this recipe.
For those of you who don't drink alcohol, it will evaporate when you cook the sauce for at least 20 to 30 seconds. Alcohol evaporates at 172°F (78°C), so any sauce or stew that is simmering or boiling is certainly hot enough to evaporate the alcohol.