For the puff pastry: Mix the flour and salt and add water little by little while kneading until you obtain a soft and smooth dough.

Form a ball, cover and let rest for a few minutes.
In a freezer bag, knead the butter to give it the same consistency as the soft dough.

Form a rectangle with the butter, 1cm thick. Roll out the ball of puff pastry to have a rectangle twice as large.

Place the rectangle of butter on one end of the dough and fold the other end over it. Press the sides and spread using the rolling pin.
Perform a double fold. You will need 4 and between two folds we put the dough in the refrigerator for 20 minutes.

Let the dough rest for 30 minutes in the refrigerator. Divide it in half, spread it out and cut out two discs.

For the frangipane cream:
In a saucepan, bring the whole milk to a boil. Whisk together the egg yolk and 20g sugar. Add the cornstarch and whisk well.

Pour the hot milk over this preparation in two batches while mixing. Return the mixture to the heat and continue to mix until you obtain a smooth cream.
Mix 80 g of sugar with the soft butter. Add the egg and insist, mixing well.

Mix the almond cream and pastry cream. Cover and refrigerate.
Place the frangipane cream on one of the discs, a bean, cover with the second disc by sealing the ends of the pancake.

Brown the pancake with a brush in two batches. Bake at 180 degrees for 30 minutes.