In a medium bowl, whisk together the granulated sugar, ground cinnamon, and salt until evenly combined.

Lightly flour a clean work surface. Unfold the puff pastry and gently roll or stretch it into an even rectangle.

Brush the entire surface of the puff pastry with the melted butter, reaching all the way to the edges.

Sprinkle the cinnamon sugar mixture evenly over the buttered pastry and gently press it into the surface so it adheres.

Using a sharp knife or pizza cutter, cut the pastry lengthwise into 1 inch wide strips.

Pick up each strip, hold both ends, and twist several times to create a tight spiral.

Preheat the air fryer to 350°F.

Arrange several twists in a single layer in the air fryer basket, leaving a little space between them for air circulation.

Air fry at 350°F for 8 minutes, flipping halfway through, until the twists are golden brown and crisp.

Transfer the cooked twists to a wire rack to cool slightly while you cook the remaining twists in batches.

For the optional glaze, whisk the powdered sugar with the milk or water in a small bowl until smooth.

Drizzle the glaze over the slightly cooled cinnamon twists and serve warm or at room temperature.