Cut bread into 1' cubes. Butter a 13 x9 baking dish
In a large mixing bowl, whisk together the eggnog, milk, egg and spices.
Spread bread cubes in prepared baking dish and pour eggnog mixture over. Cover and refrigerate overnight.
In the morning, preheat oven to 350F.
In a small bowl, stir together the flour, spices and brown sugar. Work the butter in until crumbles have formed and butter is fully incorporated. Sprinkle over casserole.
Cover with foil and bake for 30 minutes. Uncover and bake for 30 minutes longer. Let cool slightly before serving.