If baking immediately after prep, preheat oven to 350 degrees F. Coat a 9×13 baking dish with cooking spray and set aside.
Spread bread pieces into the bottom of prepared pan. In a medium bowl, combine the eggs, milk, vanilla and 1/4 cup sugar. Mix well and pour evenly over the bread.
In a separate bowl, combine the apples, lemon juice, brown sugar, 1/4 cup sugar, butter, cinnamon and nutmeg. Mix well and pour evenly over the top. Tuck some of the apple slices down between the bread creases.
If baking immediately, bake in the preheated oven for 45 minutes. If storing overnight, cover pan with foil and refrigerate for up to 48 hours. When ready to bake, remove foil and bake at 350 degrees F for 60 minutes. Serve warm with syrup.