First of all, pour the flour into a bowl, put the yeast in the center, also add eggs, sugar, butter in chunks (the 100 g of the dough), vanilla and milk and start kneading, then add the salt and continue to mix. to work.
Continue to knead until you get a homogeneous dough, then put it in a warm place and away from drafts and let it rise for at least 2 hours or until doubled.
Take back the dough, divide it into 9 equal parts and roll them all into thin circular sheets.
Melt the remaining butter (the 80 g intended precisely for puff pastry) and overlap the dough sheets, first brushing each disc with plenty of melted butter.
Once all the discs are overlapped, gently roll out with a rolling pin to form a rectangle, then with a smooth blade knife cut 10 strips from the rectangular sheet, cutting in the direction of the short side.
Roll each strip to obtain the spiral shape.
Arrange the snails on a baking sheet lined with parchment paper and let them rise again for at least 1 hour, then brush with 1 egg white, sprinkle with sugar and bake for about 25 minutes at 180 ° C in a pre-heated ventilated oven.
The puffed snails are ready: if you can, at least let them cool before eating them.