In a shallow bowl, mix sugar and cinnamon until evenly combined. Set aside so it’s ready as soon as the churros come out of the oil.

In a saucepan, combine water, butter, sugar, and salt. Bring to a gentle boil, then remove from heat and stir in the flour all at once. Mix until the dough forms a smooth ball and pulls away from the sides of the pan.

Allow the dough to cool slightly, then add eggs one at a time, mixing thoroughly after each addition. The dough should become smooth, glossy, and thick enough to hold its shape when piped.

Heat oil in a deep pan to a steady frying temperature. Maintaining consistent heat is key to preventing greasy or undercooked churros.

Transfer the dough to a piping bag fitted with a star tip. Pipe strips of dough directly into the hot oil, cutting them with scissors to the desired length. Fry until golden brown, turning occasionally for even cooking.

Remove churros with a slotted spoon and drain briefly on paper towels. While still warm, roll them in the cinnamon sugar mixture until evenly coated.