Preheat your oven to 350°F (175°C).
Wash and core the apples, leaving the bottom intact.
Mix brown sugar and cinnamon in a small bowl.
Sprinkle the mixture inside the hollowed apples.
Add chopped nuts and raisins if desired.
Place apples in a baking dish and dot with butter.
Pour 1/2 cup of water into the dish to create steam.
Cover with foil and bake for 20 minutes.
Remove foil and bake for an additional 10 minutes.
Serve warm, topped with vanilla ice cream.