Difficulty:[usr 2 ]
Preheat the oven to th. 7 (210°).
Unwrap the squares of puff pastry and cut 9 of them in half lengthwise, reserve the others for later use. You should obtain 18 rectangles of 7 cm x 14 cm. Prick them with a fork, brush them with egg yolk, dust them with icing sugar and slide them into the oven. Let them cook for about 5 minutes, then take them out and flatten them with the bottom of a saucepan. Let them cook for a few more minutes so that they are golden brown.
At the same time, whip the very cold cream into a firm whipped cream, incorporating the vanilla sugar.
Take out the rectangles of dough and let them cool.
Put the cream in a piping bag fitted with a fluted tip.
Spread a layer of cream on 6 rectangles of cooled dough. Dust lightly with cocoa, sprinkle with broken chestnuts, cover with a rectangle of dough and repeat the operation. Place the last rectangles of dough on the mille-feuilles.
Decorate with a touch of whipped cream and cherries.
Serve immediately.
