Preheat oven to 350°
butter a 13"x9" baking dish
Peel the apples and dice them into 1/2 inch cubes. Cut the Panettone into 1" cubes.
Separate two eggs, whites from yolks. Set aside the egg whites.
In a large bowl, add the three whole eggs plus the two egg yolks. Whisk the eggs with the 1/2 cup of sugar and then whisk in the milk, cream, cinnamon, and vanilla.
In another large bowl, place the cubed panettone and the diced apples. Pour 2/3rds of the milk and cream mixture over it and allow to sit for 10-15 minutes to absorb the liquid. Stir every 5 minutes to make sure the cubes are evenly absorbing the liquid.
While the pannetone rests, whip the egg whites (using an electric mixer) until thick and fluffy. Then add the extra tablespoon of suger and whip until stiff.
Gently fold the beaten egg whites into the bowl with the soaking pannetone. Place this mixture into the buttered pan and then pour the remaining 1/3rd of the custard mixture over it the panettone in the pan.
Bake in the oven for about 35 minutes or until fairly set. It can be a little soft in the center. Cook to 155 degrees F on an insta-read thermometer.
Allow to cool for at least 15 minutes before serving so that the custard sets up. Garnish with whipped cream.