Preheat the oven to 350°F (175°C) and gather your baking dish.

In a mixing bowl, combine peeled and sliced apples with granulated sugar, brown sugar, lemon juice, ground cinnamon, ground nutmeg, all-purpose flour, and vanilla extract. Stir until well-coated, then transfer to the prepared dish.

In another bowl, whisk together all-purpose flour, rolled oats, brown sugar, ground cinnamon, and salt. Add the cold, cubed butter, mixing until coarse crumbs form.

Evenly sprinkle the crumble topping over the apple filling.

Place the dish in the preheated oven and bake for 40–45 minutes, or until golden brown and bubbly.