Coat a 9-by-13-inch pan with nonstick spray. Set aside.
In a large bowl, whisk Eggology egg whites, beat and combine with sugar. Add milk and vanilla; mix well.
In a small bowl, combine cinnamon and sugar; set aside.
Place 1/3 of bread cubes on the bottom of prepared pan. Pour 1/3 of the milk-and-egg mixture on top of the bread. Sprinkle bread cubes with 1 cup of blueberries and 1/3 of the cinnamon sugar. Repeat layering 2 more times. Pour melted butter over top, covering as much surface as possible. You can prepare the dish up to this point as early as the night before, but at least half an hour before. Cover with plastic wrap; refrigerate.
Bake for 45 minutes, or until a sharp knife inserted halfway between the center and the edge comes out clean. Remove from oven and let stand for about 10 minutes before cutting into 8 servings.