Add brioche bread to a buttered baking dish
In a separate bowl combine eggs, milk, half and half, vanilla, and all the spices
Pour mixture over the bread and make sure it gets in between the slices
Leave in fridge overnight
Remove from fridge on Christmas morning
Preheat oven to 350°F
Make the brown sugar topping by combining melted butter, brown sugar, cinnamon, and nutmeg
Drizzle topping over the casserole
Bake for 35-45 minutes until bread is puffy and cooked through
