Try this one when you are looking for something a bit unusual and out of the ordinary. A recipe by British chef Antony Worrall Thompson which I saw prepared on a BBC cooking program. I was intrigued by boiling then using the oranges whole, but admit that it makes for a well-flavored cake. I love the mascarpone cream as well because I cannot eat whipped cream but the mascarpone gives me very nearly the same mouth feel, and I find it delicious ! Preparation time includes the time to boil the oranges, but remember to PLAN in ADVANCE! As for the vanilla sugar, there are several recipes here on 'Zaar if you are unable to buy this at your local grocery.