1In a saucepan, bring water, butter, and salt to a boil. Once butter has melted, add all the flour at once and stir vigorously until a smooth, non-sticky dough forms.
2Let the dough cool slightly, then incorporate eggs one at a time, mixing well after each, until you get a smooth, pipeable paste.
3Transfer the dough to a piping bag with a star tip.
4Line the air fryer basket with parchment paper and pipe strips of dough about 10-12 cm long, in the shape of churros.
5Lightly spray the churros with cooking spray.
6Preheat the air fryer to 180°C (350°F).
7Cook churros in the air fryer at 180°C for 10-12 minutes, turning halfway, until golden and crispy.
8While still hot, roll the churros in a mixture of sugar and ground cinnamon until evenly coated.