In a saucepan, combine water, butter, sugar, and salt over medium heat. Let it come to a soft boil.
Once boiling, dump in the flour and stir like you're stirring your way out of trouble—until the dough pulls away from the sides.
Take it off the heat. Stir in the vanilla, then beat in the eggs one at a time. It’ll look weird at first, but trust the process.
Transfer the dough into a piping bag fitted with a large star tip (or whatever tip you’ve got).
Pipe 1-inch pieces onto a parchment-lined tray and chill for 10 minutes to help them hold shape.
Preheat your air fryer to 375°F. Lightly spray the basket with oil.
Air fry the churro bites in batches for 6-8 minutes or until golden and puffed.
While still warm, toss them in the cinnamon sugar mixture. Do it fast—this is where the magic sticks.
Serve warm with chocolate sauce, caramel, or, let’s be honest, just a napkin and your fingers.