In the bowl of the kneader we mix the flour and salt. Lightly heat the milk and add the sugar and yeast. We remove to integrate. We add it to the container with the flour and salt along with the egg and mix to integrate.
Finally we add 50 grams of the butter (the rest we reserve for the filling), at room temperature, and knead for about 12-14 minutes or until the dough is smooth, silky and all the ingredients are integrated.
We transfer the dough to a greased container, cover it with a kitchen cloth and let it rise until double your volume. This will depend on the ambient temperature, it took us a couple of hours.
After this time we press the dough with the fist to degas, we make a ball with it and transfer it to a sheet of parchment paper. We stretch with the help of a roller, giving it a rectangle shape.
We melt the remaining 15 grams of butter and mix them with the brown sugar and ground cinnamon. We spread the resulting pasta over the dough and roll forming a cylinder. It is a very soft dough, so it must be handled gently.
With a sharp knife we cut the cylinder in eight servings and we place them inside a square or rectangular mold previously greased with a thin layer of oil. We cover the mold again and let it rise for another hour or until they increase a lot in volume.
We distribute the pearl sugar above of the rolls and we put the mold in the oven, preheated to 175 ºC with heat up and down, where we cook them for 25-30 minutes. When they are golden, we take them out and let them temper.
Now there is only prepare the frosting and, for this, we sift the icing sugar and add the water little by little, stirring after each addition. When we have obtained a thick consistency, but that can be extended, we add the glaze on top of the cinnamon rolls and ready to eat.