Using a sharp knife, make 1/4-inch-deep slashes in the rib meat between the bones, without cutting through. Spread all but 1 tablespoon of the spice rub over the ribs and into the slashes and let stand for 5 minutes.
Meanwhile, in a small saucepan, combine the hoisin sauce, ketchup and the remaining 1 tablespoon of spice rub and bring to a boil. Cook for 1 minute, then transfer to a bowl.
Light a grill. Lightly brush the ribs with oil and grill over a moderately high fire, turning frequently, until the ribs are sizzling and cooked through, about 25 minutes. Brush the ribs with half of the hoisin glaze and grill for 2 minutes longer. Transfer the ribs to a cutting board and cut in between the bones. Serve the ribs with the remaining hoisin glaze on the side.
Asian Five-Spice Rub
Chinese five-spice rub is a bold mix of cinnamon, clove, fennel seed, star anise and Sichuan peppercorn. Grace Parisi loves the way these exotic, fragrant spices flavor fabulously sticky spareribs glazed with sweet hoisin sauce.
In a small bowl, combine all of the ingredients, pressing out any lumps of brown sugar.