Place water, 1/2 cup butter (sliced into tablespoons), and salt in a large saucepan. Heat over medium heat until butter is melted and stir occasionally until mixture boils.
Turn off the heat and stir in the flour. A thick paste will form.
Add eggs, one at a time, mixing well after each addition (work fast to avoid cooking the eggs). It’ll seem like the eggs don’t want to mix in but they will.
Place the churro batter in a large pastry bag fitted with a star or 1M tip.
Pipe churros in desired size and shapes onto air fryer basket. (This recipe makes approximately 60 3-inch long churros or 25 7-inch long churros. You may need to work in batches depending on the size of your air fryer.
Spray the churros with nonstick cooking spray. This will help them brown.
Preheat the air fryer for about 10 minutes to 375°F. Air fry them 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.
To make Chocolate Ganache:
Place 1/3 cup heavy whipping cream and 1 cup semi-sweet chocolate chips in a microwave safe cup or bowl. Heat for 1 minute, then whisk until smooth.