In a saucepan, combine water, butter, sugar, and salt. Bring to a boil over medium heat.
Remove from heat and stir in flour until a dough forms.
Let cool for 5 minutes. Add eggs one at a time, mixing well after each addition, then stir in vanilla.
Transfer dough to a piping bag fitted with a star tip.
Preheat air fryer to 375°F. Line basket with parchment and lightly spray with cooking spray.
Pipe 4-inch strips of dough into the basket, cutting with scissors. Do not overcrowd.
Air fry for 10 minutes or until golden brown and crisp.
Mix sugar and cinnamon in a bowl. Roll warm churros in the mixture and serve.