Put the flour in a bowl, pour the yeast dissolved in the just warm milk in the center and start kneading, then add the egg, then add salt and butter into small pieces.
Continue to knead for at least 10 minutes, until the dough is strung, then cover the bowl well and let it rise in a sheltered place for about 2 hours or until the dough has at least doubled in volume.
Once doubled, take the dough back, deflate it with floured hands and divide it into 6 larger pieces (about 80 g each) and 6 small ones (about 20 g each).
Pirl the pieces of dough to form balls, then arrange them on the baking sheet lined with parchment paper, well spaced, and let rise for another 2 hours.
Once risen, press a finger in the center of the larger balls and place the smaller balls on top, pressing gently.
Then brush with lightly beaten egg yolk and cook for about 20 minutes in a preheated convection oven at 170 ° C.
The brioches with salted tuppo are ready, let them at least cool before serving.