Slice bread into 1'' slices and then cut slices in half. Place in large bowl. In a smaller bowl put milk, eggs, sugar, vanilla, cinn, nutmeg, and salt. Beat with a fork until mixed and pour over bread. Toss bread and let sit for 30 min to 1 hour occasionally mixing gently. Bread should soak up all the liquid. Generously butter a glass casserole with a tablespoon of butter. Place bread evenly in layers in the buttered casserole dish. Top with diced apple. Bake 15 min at 350*. remove from oven and Crumble topping over bread. Return to oven and bake additional 30 ~ 40 min at 350*. French toast should be puffed up and golden brown. Keep warm in oven until ready to serve.