Trim crusts from bread. Arrange half of the bread in a by 9 by 13-inch baking dish coated with cooking spray.
Combine milk, 1 1/2 cups egg substitute, half-and-half, and 1/2 cup sugar in a large bowl, stirring with a whisk. Pour half of milk mixture over bread in dish.
Combine 1/2 cup egg substitute, 1/2 cup sugar, vanilla, nutmeg, and cheeses in a food processor or blender; process until smooth. Pour cream cheese mixture over moist bread in dish. Top with remaining bread; pour remaining milk mixture over bread. Cover and refrigerate 8 hours overnight.
Preheat oven to 350 degrees F.
Let the dish come to room temperature about 30 minutes. Uncover and bake for 55 minutes. Let stand 10 minutes before serving. Sprinkle with cinnamon-sugar, if desired.