In a small bowl, combine first seven ingredients; rub over roast.
In a large skillet, heat oil; brown roast on all sides. Place on a rack in a shallow baking pan. Bake, uncovered, at 325℉ for 1.5 hours.
Combine topping ingredients; spread over top of roast. Bake 1–1.5 hours longer or until meat thermometer reads 160℉. Let stand 10 minutes before slicing.