Thinly slice apple. Cube French bread.
Grease a 9″x13″ casserole with cooking oil.
In a large bowl, combine eggs, milk, vanilla extract, ground cinnamon, and brown sugar. Whisk egg mixture.
Add 1/2 of the cubed French bread to casserole dish, add 1/2 of the sliced apples, then pour 1/2 of the egg mixture. Add the rest of the French bread, then add the rest of the sliced apples, then the rest of the egg mixture. Remember to spread cubed French bread and sliced apples out evenly.
Wrap the casserole dish with saran wrap and refrigerate for four hours, or up to overnight.
In another small bowl, combine all "stresuel" topping and mix well. Refrigerate topping as well for four hours, or up to overnight.
Pre-heat oven to 350 degrees F.
Unwrap casserole dish. Stir stresuel topping with a spoon. Top casserole dish with the stresuel topping.
Bake for 40-45 minutes, or until the center is fully cooked.
Sprinkle with powdered sugar.
Serve with maple syrup and enjoy!