Preheat oven to 350°F. Grease a 9×13 inch baking pan. Rip up raisin bread into bite sized pieces and layer at the bottom of the baking pan.
In a large mixing bowl, whisk together the eggs, milk, vanilla, salt and nutmeg. Pour evenly over top of the bread.
Mix together brown sugar, raisins and cinnamon and sprinkle evenly on top of the casserole. Cover with aluminum foil. Bake for 30 minutes. Remove aluminum foil and bake for an additional 10 minutes. Serve hot. Drizzle with maple syrup, if desired.