Step by step

Spread a thin layer of Italian custard over the puff pastry squares. Put a layer of sponge cake on top, more cream and another layer of puff pastry. Sprinkle with a generous quantity of icing sugar.

As far as the shape of your dessert is concerned, feel free to choose the one you like best!
This Italian pudding is called "diplomatic" as it was brought by a diplomat to Francesco Sforza, Duke of Milan, in 1454. Its origin is therefore Medieval.