In a medium saucepan, combine water, milk, butter, sugar, and salt. Bring to a boil over medium heat, stirring frequently.

Once boiling, remove from heat and stir in the flour all at once with a wooden spoon. Cook for 2 more minutes, stirring constantly, to release moisture.

Transfer the dough to a mixing bowl and beat with an electric mixer for 2 minutes to cool it down.

Add eggs one at a time, ensuring each is fully incorporated before adding the next. Beat until the dough is smooth and shiny.

Heat oil to 370°F in a deep pan.

Pipe the dough into 6-inch lengths directly into the hot oil, cutting to separate. Fry for 1.5 minutes on each side or until golden brown.

Transfer the cooked churros to a paper towel-lined plate to drain excess oil.

While they're still warm, roll them in the cinnamon sugar mixture.