Put the water, butter, and sugar in a saucepan. Bring to a boil, then turn the heat to low.

Add the flour and stir over low heat for about 2 minutes, until the dough comes together and no longer sticks to the pan.

Transfer the dough to a bowl. Add the eggs one at a time, mixing each one into the dough before adding the next.

Transfer the dough to a piping bag fitted with an 8-star tip. Double up the piping bags to prevent the thick dough from bursting the bag.

Pipe strips onto parchment paper and cut the paper into portions for transferring the strips to the oil.

Heat the cooking oil over medium-high heat. Lower the piped dough into the oil using the parchment and remove the paper with tongs once the dough releases. Fry, turning, until golden brown, about 3–4 minutes. Lift out and drain.

Mix the coating sugar with the cinnamon. Roll the fried churros in the mixture.