In a medium sauce pan, bring the water, butter, sugar and the pinch of salt to a boil over medium heat. Once the mixture boils, reduce the heat and add in the flour and mix rapidly using a wooden spatula. Continue stirring the mixture until the mixture thickens and does not stick to the sides of the pot.
Transfer the mixture to a stand mixer bowl or heat proof bowl and mix using a paddle attachement. This will allow the churro dough to cool down so we can add the eggs. This process will take between 3-5 minutes.
Once the churro dough is a little bit cooler add in the eggs one at a time while continuing to mix. The mixture will become a lot more sticky. At this point, transfer the churro mixture to a piping bag fitted with a star tip. I used the Wilton 1M
On a parchment lined baking sheet pipe 3-4 inch long churros. Cut the end using a pair of scissors or knife. Place the baking sheet in the freezer for 30 minutes.
3 minutes before your churros are ready to be baked, preheat the air fryer to 360F. Gently remove the frozen churros from the parchment paper and place them into the air fryer basket and bake for 13-14 minutes. Depending on what air fryer you have you might have to bake these churros in multiple smaller batches. Place the leftover churros in the freezer so they don't get soft.
In a shallow bowl or plastic bag combine the sugar and the cinnamon. Place the baked churros in the sugar mixture as soon as they come out of the air fryer, toss them in the cinnamon sugar mixture to coat them evenly.
Serve with dulce de leche, sweetened condensed milk or even Nutella!