Prepare the Dough:

In a medium saucepan, combine the water, butter, sugar, and salt. Heat over medium heat until the butter is melted and the mixture comes to a simmer. Add the flour all at once, stirring vigorously until the dough pulls away from the sides of the pan. Remove from heat and let the dough cool for about 5 minutes.

Add the Egg and Vanilla:

Once the dough has cooled slightly, add the egg and vanilla extract. Mix until smooth and the egg is fully incorporated.

Heat the Oil:

Heat vegetable oil in a deep frying pan or pot to 375°F (190°C).

Pipe the Churros:

Transfer the dough to a piping bag fitted with a star tip. Pipe 4–5-inch strips of dough into the hot oil, cutting them with scissors. Fry 3–4 churros at a time for 2–3 minutes per side, or until golden brown and crispy.

Coat the Churros:

In a small bowl, mix the sugar and cinnamon. As soon as the churros are done frying, remove them from the oil and toss them in the cinnamon-sugar mixture while they’re still warm.

Serve and Enjoy:

Serve the cinnamon churros warm for a delightful dessert or snack!