Place water, butter, salt (if using) in cooking pan. With high heat boil the water then turn the heat off.
Sift the flour and add to the water mixture. Stir the flour until combine then put the pan back on low heat. Stir it mixture until it forms a ball. Turn the Heat off.
Transfer the dough into a big mixing bowl. Using hand mixer in medium speed, beat the dough for 1-2 minutes to let the dough cool a little.
Add the eggs one by one while beating with medium speed until all the eggs incorporated.
Add the grated cheese and baking powder and mix well. Put the batter in a piping bag and pipe on a non stick baking tray or baking tray lined with parchment paper.
Bake 200C for 20 minutes then lower temperature to 130C for 40-50 minutes until crispy.
