Preheat oven to 375°F (190°C).
Toss apples with granulated sugar, lemon juice, cinnamon, and nutmeg in a bowl.
Spread apple mixture in a greased baking dish.
In another bowl, mix flour, brown sugar, and oats.
Cut in butter until crumbly.
Sprinkle topping evenly over apples.
Bake for 30-35 minutes until golden and bubbly.
Serve warm with ice cream or whipped cream.
