Beat the sugar, vanilla sugar, and softened butter, then add the ground almonds.
Scrape the seeds from the vanilla pod and add them to the mixture.
Add 2 whole eggs, then the pistachio paste.
Arrange a circle of dough, spread the almond pistachio cream on top, leaving a 2 cm border around the edge, which should be lightly moistened with a brush and water.
Place the bean inside and cover with the second, slightly larger disc of puff pastry. Seal the edges by pressing down all around.
Brush the top of the cake with beaten egg.
Place the galette in the refrigerator for 30 minutes, remove it, draw patterns with a knife blade without piercing the dough, and brown it a second time.
