Preheat your oven to 350°F (175°C) and lightly grease a 9x13-inch baking dish.
In a mixing bowl, toss peeled and sliced apples with white sugar, cinnamon, and nutmeg, then spread them evenly in the dish.
In another bowl, combine brown sugar, flour, oats, and cinnamon. Add cold diced butter and mix with a pastry cutter or fork until crumbly.
Sprinkle the crumble topping evenly over the apples.
Bake for 35-40 minutes, or until the topping is golden brown and the apples are bubbling.
Let it cool for 5-10 minutes before serving.
Serve warm with vanilla ice cream, whipped cream, or caramel drizzle for extra indulgence.
Enjoy and store any leftovers in an airtight container for up to 3 days.