Season both sides of rack with salt and pepper 20 minutes before cooking. Sear in heavy saute pan with olive oil until rack is well caramelized. Set aside.
Preheat oven to 350 degrees F. In same pan, add sliced onions, ginger, cinnamon, star anise and butter. Slowly cook until onions are well caramelized. Add maple sugar and cook for 2 minutes.
Deglaze with cider, adjust salt and pepper to taste and reduce until a glaze forms. Completely cover rack with half of onion compote. Transfer to roasting pan and place in oven. Cook at 20 minutes per pound or until internal temperature is 150 degrees F. Halfway through cooking time, pour over remaining half of onion compote. Remove from oven and let rest for 10 minutes before slicing. Discard the cinnamon stick and star anise.