Preheat oven to 375°F. Place apples, cut-side-up, in a baking dish. Dot apples with butter, drizzle with maple syrup and sprinkle with cinnamon. Pour 1/4 cup water into bottom of the dish and cover it with foil. Bake until apples are soft, about 35 minutes. Uncover and bake another 10 minutes. Transfer apples to a serving dish and pour the cooking liquid over the top. Allow to cool 5 minutes before serving. Top with granola and whipped cream, if desired.
Place butter in a glass baking dish and cook on high power just long enough to melt it, about 10 seconds. Add maple syrup and cinnamon and cook for 10 more seconds. Place apples, cut-side-down, in dish, cover and cook for 3 minutes, until tender but not mushy. Allow to cool 5 minutes. Serve cut-side-up, topped with granola and whipped cream, if desired.