Mix instant yeast directly with flour, then add sugar, salt and warm milk and gently start mixing the ingredients. Add egg yolks and after combining the ingredients and brief kneading add soft butter. Knead until the dough is smooth and elastic, about 15 minutes.
From fresh yeast you need to make first a mixture: crumble yeast at room temperature with 1 teaspoon sugar until it dissolves. Then add 2 tablespoons flour and half of warm milk. Mix well and set aside for 10-15 minutes to rise. Add the mixture to the flour, then add the remaining sugar, salt and pour the remaining milk. Start mixing the ingredients, add egg yolks and finally soft butter. Knead thoroughly until elastic and smooth dough (about 15 minutes, until it pulls away from your hand). Cover with a cloth and set aside in a warm place to rise, for about 1 1/2 hours.
Place the dough on a work surface, work a little removing air bubbles, form a roll and divide it into 16 equal parts.
If making filled rolls: flatten the first piece of dough in your hands into a cake, spread 2 teaspoons of Nutella, seal the edges of the dough well, then form in your hands a neat roll.
If making unfilled rolls: from each piece of dough we form a neat roll.
Arrange the formed rolls on 2 baking sheets lined with paper at intervals. Set aside for about half an hour to rise.
Preheat the oven to 190°C. Carefully brush the top of the rolls with beaten egg (using a brush).
Bake each sheet in turn for about 15 minutes until golden.
