In a medium saucepan, combine 1 cup of water, 1/4 cup of unsalted butter, 1/4 teaspoon of salt, and 2 tablespoons of sugar. Heat over medium-high until it reaches a boil, stirring occasionally.

Reduce the heat to low and gradually add 1 cup of all-purpose flour, stirring constantly until the dough pulls away from the sides of the pan.

Allow the dough to cool for about 5 minutes, then add 1 large egg and 1 teaspoon of vanilla extract. Mix until smooth.

Preheat your air fryer to 375°F (190°C) for about 5 minutes and prepare the basket with nonstick cooking spray.

Transfer the churro dough into a piping bag. Pipe small twists of dough about 2 inches long into the prepared air fryer basket.

Lightly brush the piped churros with melted butter. Air fry for 10 to 12 minutes until golden brown.

Remove the churro bites and toss in a mixture of 1/2 cup of white sugar and 1 tablespoon of cinnamon immediately.