Slice each piece of bread into 4 even strips, about 1 inch wide.
Stir the granulated sugar and cinnamon together on a shallow plate and set aside.
In a medium bowl, whisk the eggs until fully broken up. Add the pumpkin puree, milk, brown sugar, vanilla, cinnamon, nutmeg, and salt, and whisk until smooth.
Preheat the air fryer to 325°F (165°C) and grease the basket.
Dip each bread strip into the custard, shake off the excess, then roll it in the cinnamon sugar.
Working in batches, arrange the strips in a single layer with space between them. Air fry at 325°F for 4 to 6 minutes, turning halfway through, until golden and crisp.
Serve hot with maple syrup for dipping.