Put a silicone baking mat on a baking sheet and spray with oil spray.
In a medium saucepan add water, butter, sugar, and salt. Bring to a boil over medium-high heat.
Reduce heat to medium-low and add flour to the saucepan. Stirring constantly with a rubber spatula cook until the dough comes together and is smooth.
Remove from heat and transfer the dough to a mixing bowl. Let cool for 4 minutes.
Add eggs and vanilla extract to the mixing bowl and mix using an electric hand mixer or stand mixer until dough comes together. The mixture will look like gluey mashed potatoes. Use your hands to press lumps together into a ball and transfer to a large piping bag fitted with a large star-shaped tip.
Pipe churros onto the greased baking mat, into 4-inch lengths and cut end with scissors.
Refrigerate piped churros on the baking sheet for 1 hour.
Carefully transfer churros with a cookie spatula to the Air Fryer basket, leaving about ½-inch space between churros. Spray churros with oil spray. Depending on the size of your Air Fryer you have to fry them in batches.
Air fry at 375 degrees F for 10-12 minutes until golden brown.
In a shallow bowl combine granulated sugar and cinnamon.
Immediately transfer baked churros to the bowl with the sugar mixture and toss to coat. Working in batches. Serve warm with Nutella or chocolate dipping sauce.