Preheat the oven to 350F.

Peel, core and cut the apples into chunks. Place the apples in a bowl and add the lemon juice, sugar, salt, ground cinnamon and ground nutmeg and set aside.

For the topping: Combine the flour, sugar, brown sugar, oatmeal and butter in a bowl. Mix well until well combined.

Pour the apple mixture in the baking dish. Sprinkle the topping evenly over the apples.

Bake until the topping is crisp and golden brown and the apple filling bubbles slowly, about 50 minutes. Serve warm.