First prepare the cream: beat the egg yolks with the sugar, then add the cornstarch and finally milk and vanilla.
Transfer everything into a saucepan, start cooking, over low heat, stirring, and bring to a boil and thicken.
Cover with plastic wrap and let cool.
At this point, start composing your puff pastry: place the crackers on a serving dish big enough to contain half (I didn't have any and I split it into 2 plates).
Spread 1/3 of the cold cream on the first 10 crackers.
Add 1/3 of the chocolate drops, then create the second layer of crackers.
Add cream and chocolate again, then create the last layer of crackers, cream and chocolate chips.
The millefeuille of crackers is ready: let stand 1 hour in the fridge, then decorate with icing sugar and serve.