Spray your baking pan with cooking spray.
Then add the bread cubes into the pan, and add the cream cheese, and blueberries.
In a large mixing bowl, mix the eggs, milk, vanilla, and maple syrup, and pour into the baking pan. Cover and refrigerate overnight.
Then add the baking pan to the air fryer, and set the temperature to 320 degrees F, air fryer setting and cook for 10 to12 minutes, or until golden brown.
While the French toast casserole is baking, add the sugar, cornstarch, and water, to a low simmer, simmer for a couple of minutes, and then add in the blueberries, simmer for another 10 minutes until the blueberries open. Mix in the butter and then pour over the french toast, right before serving.