Trim fat from pork. Combine sugar and next 3 ingredients (sugar through pepper). Rub pork with spice mixture.
Place pork on a broiler pan coated with cooking spray; insert a meat thermometer into thickest portion of tenderloin. Bake at 400° for 10 minutes. Combine hoisin, orange juice, and oil in a small bowl; brush over tenderloin. Bake for an additional 15 minutes or until thermometer registers 160° (slightly pink).
This is a really easy and very yummy recipe. I've made it several times; this last time I tripled the sauce, heated up the excess, and drizzled it over the sliced pork and a bed of udon noodles. Be sure to use a good hoisin sauce such as Koon Chun (which most every Asian grocery store carries, as do many regular groceries).