Whisk the eggs, brown sugar, milk, ground cinnamon, vanilla extract, and kosher salt in a large mixing bowl until smooth and creamy.

Cut stale bread into bite-sized cubes and gently fold into the egg mixture, allowing to soak for 5 minutes.

Preheat your air fryer to 350°F (175°C). Optionally, spray the basket with non-stick cooking spray.

Arrange the soaked bread cubes in a single layer in the air fryer basket, avoiding overlap.

Air fry the bread cubes at 350°F (175°C) for 8-10 minutes, shaking the basket halfway through.

Once cooked, serve immediately with optional toppings like maple syrup, fresh berries, or whipped cream.