In a medium saucepan, combine 1 cup of water, 1/3 cup plus 1 tablespoon of unsalted butter, 1 teaspoon of salt, and 2 tablespoons of sugar. Bring to a boil, then reduce heat and add 1 cup of plain flour until smooth.

Remove from heat and let the dough cool for 4-5 minutes. Add in 1 large room-temperature egg and 1 teaspoon of vanilla essence, mixing until smooth.

Transfer your churro dough into a piping bag fitted with a star tip.

Preheat air fryer to 375°F (190°C) for about 5 minutes, spraying the basket with nonstick spray.

Pipe churro shapes into the air fryer basket, avoiding overcrowding.

Lightly brush with melted butter and cook for 10-12 minutes or until golden brown.

Mix together 1 cup of white sugar and 1 tablespoon of cinnamon in a shallow bowl.

Toss churro bites in cinnamon-sugar immediately after frying while still warm.