Place water, 2 tablespoons softened butter, 2 tablespoons sugar, vanilla, and salt in a medium saucepan. Heat over medium heat until butter is melted and stir occasionally until mixture boils.
Turn off the heat and remove pan from the stove. Stir in the flour with a wooden spoon. A thick paste will form. Make sure to do this off the heat and off the stove, so that the mixture can cool as you stir it.
Transfer the dough to the bowl of a stand mixer and let sit 1 minute to cool. Attach the paddle attachment and add eggs, one at a time, mixing well after each addition (work fast to avoid cooking the eggs). You can also use a large bowl with a hand mixer but work fast.
Place the churro batter in a large pastry bag fitted with a star or 1M tip.
Pipe churros in desired size and shapes straight onto the air fryer basket. (This recipe makes approximately 60 3-inch long churros or 25 7-inch long churros.) If the dough sticks to the tip you can use a knife or kitchen scissors to cut the dough at the piping tip.
Spray the churros with nonstick cooking spray. This will help them brown.
Air fry them at 375°F until golden-brown, depending on size this will take about 10 minutes depending on your air fryer. Watch the first batch to make sure they don't burn and so you'll know how long they take to cook.
Stir together sugar and cinnamon while the churros are frying. Toss hot churros in the cinnamon sugar to coat. Serve right after frying for best taste.