For this recipe you will need a heavy, flat baking tray and a 25cm/10in fluted flan tin ... melt the chocolate and the butter together in a heatproof bowl over a pan of simmering water.

Making one batter, you'll have a 3 layer cake : a chocolate flan, a chocolate custard and a chocolate sponge cake ! Separate egg whites from yolks. Whisk the yolks with white and brown sugar.