> 1/4 cup (1/2 stick) unsalted butter
> 1/4 cup plus 1 tbsp sugar, divided
> 1 cup water
> 1 cup all-purpose flour
> 2 large eggs
> 1 tsp vanilla extract
> Cooking spray
> 1 tsp cinnamon
> 1/4 cup chocolate-hazelnut spread, for dipping
Line a small baking sheet with parchment. Fit a large star tip (like 1m) in a piping bag or gallon-size resealable plastic bag. To a medium pot on medium-high, add the butter, 1 tbsp sugar, and the water. Add a pinch of salt and bring mixture to a boil. Once boiling, reduce heat to medium-low. Add the flour and stir rapidly with a wooden spoon until a dough forms. Cook 4–5 min., stirring constantly, until mixture has thickened and does not stick to sides of pot.
Transfer dough to the bowl of a stand mixer. With a paddle attachment, mix dough on medium-low 3–5 min., until slightly cooled. Once cooled, add the eggs 1 at a time, mixing constantly until fully incorporated. Add the vanilla and mix until combined. Transfer dough to prepared piping bag. Pipe dough into 3–4-inch lines, using kitchen scissors to cut off dough pieces. Freeze 30 min.
Preheat air fryer to 375°F. In batches, add churros to air fryer basket, leaving space between churros. Spray tops lightly with the cooking spray. Cook 10–12 min., until golden brown. Meanwhile, in a shallow bowl, combine remaining ¼ cup sugar with the cinnamon. Transfer hot churros to sugar mixture and toss to coat. Repeat with remaining churros. Add the chocolate-hazelnut spread to a microwave-safe bowl. Microwave spread 30 sec., until warm. Add warmed spread to a serving platter with churros and serve.
Place the cooked churros in a 200°F oven to keep warm.