Line a baking sheet with parchment paper and set aside.
In a small pot, combine the water, butter, sugar, and salt and bring to a gentle simmer.
Turn the heat off and stir in the flour until the mixture turns into a soft ball. You should see a thin film still on the bottom of the pot.
Let the mixture cool for about 5 minutes.
Then transfer it to a mixing bowl or the bowl of your stand mixer with the paddle attachment and add the eggs.
Mix the dough at medium speed with an electric hand mixer or stand mixer for 1-2 minutes or until it has thickened slightly and the dough looks smooth and shiny.
Transfer the dough to a piping bag or resealable bag fitted with a large open star tip (I use a Wilton 1M) and pipe the dough into 4-inch sticks onto the parchment-lined baking sheet.
Freeze for at least 1 hour (up to overnight) until the dough is solid.
While the dough freezes, mix the cinnamon and sugar for the topping and dump it onto a small tray or plate.
Once the dough is solid, preheat the air fryer, and working in batches of 5-6, place the frozen churros into the basket of the air fryer about ½ an inch apart. (That ½ inch will allow them to expand and get crispy. If they don’t have room, they’ll be floppy and you’ll be sad.)
Spray with cooking spray or brush with a very light coat of oil and cook at 375°F for 10-12 minutes or until the ridges are browned and the dough is cooked through (I used exactly 11 minutes, but air fryers can vary by brand).
Immediately transfer to the cinnamon and sugar mixture and toss until well coated.
Serve warm with chocolate or caramel sauce if desired.
Notes
For a quick homemade chocolate dipping sauce:
1 cup water
3/4 cup sugar
1/2 cup cocoa powder (unsweetened)
1 teaspoon vanilla extract
1 pinch of salt
Preparation:
In a small pot, over medium heat, place the water, sugar, cocoa powder and a pinch of salt. Stir constantly until the sugar dissolves.
Let it heat for a couple of minutes and when the syrup thickens, remove from the heat.
Add the teaspoon of vanilla, mix again and let it cool before serving.