In a pan, combine water, butter, salt, and sugar. Bring to a boil over high heat.

Reduce heat and gradually add in the flour, stirring until the dough comes together. Turn off the heat.

Transfer the dough from the pan to a large mixing bowl and let it cool for 4-5 minutes.

Add the egg and vanilla extract, then mix everything with an electric hand mixer.

Transfer the mixture to a piping bag. Preheat the air fryer to 375°F and spray the basket with a neutral nonstick cooking spray.

Carefully pipe bite-sized churros into the air fryer, making sure not to overcrowd. You may need to cook in batches or drop spoonfuls into the basket.

Brush butter on top of the churros and air fry for 12-15 minutes until golden brown. Repeat with the remaining dough.

In a shallow bowl, mix sugar and cinnamon.

Once the churros are cooked, toss them in the sugar and cinnamon mixture until evenly coated.

If the coating doesn't stick well, brush the churro bites with melted butter or spray with water or nonstick cooking spray before rolling in the cinnamon sugar.

Serve the churro bites with chocolate syrup, honey, or Nutella.