Preheat the oven to 180¦C.
Rub the salt all over and inside each of the ducks.
Place a vanilla piece, 3 star anise and 2 cinnamon sticks inside each cavity.
Place on a roasting tray and roast for 30 minutes.
Remove from oven, pour out the fat and reserve.
Spread the maple syrup over the ducks and put the oranges on the tray.
Roast for another 30 minutes.
Remove the ducks from the tray and carve.
Bring the pan juices to a boil and remove any extra fat.
Spoon liquid over the duck.
Note: Roast the potatoes in the duck fat rather than butter - ultimately delicious.