We will begin by slightly tempering the milk and dissolve the yeast in it. We cover and leave rest for 10 minutes.
In a large bowl or in the glass of the kneading robot, add the flour, sugar, salt and add the milk and the 20 grams of egg. We begin to knead and when the ingredients are all incorporated, we add the butter little by little at room temperature, we continue kneading until it is integrated and we have a smooth and elastic dough.
Shape the dough into a tight ball and let it rise in a lightly greased bowl, covered with a cloth, until double its volume. Meanwhile, mix the filling ingredients in a bowl. except blueberriesuntil you get a cream.
When the dough has risen, we press it slightly to degas it and stretch it in the shape of a rectangle with a rolling pin. stretch out the filling and distribute the blueberries. We roll up and cut into eight portions the cylinder.
Place in a round mold and let rise again until doubled in volume again. Preheat the oven to 170 degrees Celsius. We painted with the egg that we had left over from the recipe and baked for 30 minutes. Unmold and let cool on a rack.