In a saucepan, bring water, butter, and salt to a boil.
Reduce heat to low, add flour, and stir until a smooth dough forms.
Let the dough cool slightly, then mix in eggs one at a time until smooth.
Transfer the dough to a piping bag with a star tip.
Preheat your air fryer to 375°F and spray the basket with cooking spray.
Pipe small churro shapes onto parchment paper and carefully place them in the air fryer basket.
Air fry for 6-8 minutes or until golden brown.
Combine sugar and cinnamon in a bowl and toss the warm churros to coat.
Serve with optional chocolate or caramel dipping sauce.