Put in a bowl the flour, salt and sugar. Dissolve the yeast in the milk and pour into the flour. Mix and knead until you obtain a soft dough that can be easily removed from the hands. Add the butter flakes and mix again until everything is blended. Cover the bowl with plastic wrap and let rise in a warm place for about 2 hours.
Meanwhile wash the apples, grate while maintaining the peel, squeeze between your hands to remove excess juice and dried in a pan with 3 tablespoons of sugar. Let it cool down.
Work with a spatula the butter with sugar and cinnamon.
Take the dough and roll it out on a floured surface giving a rectangular shape. Spread the butter cinnamon over the entire surface of the brioche dough, even at the edges. Distribute the grated apples and begin to roll on the longer side. When you've got a roll, cut 12 disks and place carefully on a large baking sheet covered with baking paper. Leave some 'space between a roll and the other, because it will have to rise for another hour in a warm place, away from drafts.
Preheat oven to 180 ° C and when the rolls will have doubled in volume, cook for about 35-40 minutes, making sure not to burn.