In a small bowl, pour water, yeast and a teaspoon of sugar. Set aside for 8 minutes.
While the yeast is activating, mix wet ingredients in a bowl and dry ingredients in another.
Add the yeast and the liquid ingredients to the flour. Mix well.
Put the dough on a flat surface and cover your hands in flour. This dough will be a bit sticky, so the flour will prevent it from being stuck to your hands. Do this every two minutes or every time you feel it too sticky. When working with this dough, I prefer flouring my hands rather than sprinkling it on the countertop. Knead for 10 minutes.
Place the dough in a greased bowl (use neutral, vegetal oil), flip the dough to cover it in oil, and cover with plastic film.
Set aside in a warm place. I generally leave it in the laundry room. This time, I let it rise for an hour and a half. When the weather is hot, it takes only an hour. It will be ready by the time it has doubled its size.
After the dough has rested, place it on a floured flat surface and roll it into a rectangle (about 50x30cm / 18”x11”). Spread butter on it (I used my fingers) and sprinkle the cinnamon and sugar mixture. Roll the dough and pinch the two ends to seal.
Using a sharp knife, cut into 12 equal portions. Put the rolls in a greased baking pan; cover it with plastic wrap and let rest for 30 minutes. My oven takes about 15 minutes to reach 175ºC/350ºF, so I turn it on considering the 30 minutes rest the dough needs.
Bake the cinnamon rolls for 25-30 minutes. Make the icing: mix icing sugar and milk. Pour icing over hot rolls. Serve.