1. In a medium bowl, mix brown sugar, ginger, tarragon, cinnamon, pepper, garlic powder, and salt. Rub rack of lamb with the seasonings, and place on a plate. Cover, and refrigerate for 1 hour.
2. Preheat grill for high heat.
3. Brush grill grate lightly with oil and arrange lamb ribs on grill. Cook 5 minutes on each side, or to desired doneness.