Preheat oven to 350°F. Grease a small baking dish.
Halve apples and scoop out cores. Arrange cut side up in dish.
In a bowl, mix oats, flour, cinnamon, nutmeg, salt, and butter. Add maple syrup and stir until crumbly.
Fill apple centers with oat mixture.
Bake 25–30 minutes, until apples are tender and topping is golden.
Serve warm, plain or with a drizzle of cream, a scoop of vanilla ice cream, or a dollop of whipped cream.