Preheat your oven to 375°F.
Generously butter a well-seasoned 12-inch cast iron pan or a 9×13 inch baking dish.
Slice eight pieces of bread into ½” cubes.
Chop three large, tart, baking apples (such as Granny-Smiths) into ½” cubes.
Spread half of the bread cubes in the bottom of your pan, followed by half of the apples.
Sprinkle with about ¾ cup brown sugar.
Repeat with the remaining bread cubes, apples and another ¾ cup brown sugar.
Dot the top generously with the butter.
Drizzle with ½ cup water.
Sprinkle the optional cinnamon and nutmeg over the top.
Cover with foil and bake in a 375°F oven for about 45 minutes.
Remove foil and bake for about 10 minutes longer to brown.
Serve warm.