This cake is really easy to make, especially if you buy a ready made sponge. In the UK we can buy ready made 'sponge flan' cases but I just make my own for this. The filling is more luxurious than plain old whipped cream and easy to whip up too. If you do the hot skewer thing and can make spun sugar to go on top, you will have an elegant cake with a 'wow' factor. If, like me, you are useless with the sugar, a few strawberries on top will still be beautiful. Recipe adapted from James Martin's series 'Sweet Baby James' on the BBC.