Procedure:
Preparing the pastry:
Unroll the puff pastry and cut it into rectangles or squares.
Prick with a fork, sprinkle with icing sugar and bake at 200°C for 10-12 minutes, until golden.
Let it cool completely: it will become crunchy.
Preparation of the cream:
In a bowl, whisk the egg yolks, sugar, and vanilla until pale.
Add the sifted cornstarch.
Bring the milk to the boil, then pour it slowly over the egg mixture, stirring constantly.
Return everything to the heat and cook over low heat until the cream thickens.
Cover with cling film and leave to cool.
Assembly:
In each glass, put a little cream, a few pieces of torn puff pastry, and, if you like, fruit or whipped cream.
Alternate the layers and finish with crumbled puff pastry and a dusting of icing sugar.