Preheat your oven to 350°F (175°C).
Lightly butter a 9-inch baking dish or deep pie dish.
In a large mixing bowl, combine the sliced apples and lemon juice, tossing to coat.
Add the brown sugar, granulated sugar, flour, cinnamon, nutmeg, cloves, and vanilla extract.
Toss until all apple slices are evenly coated with the spiced mixture.
Pour the apple filling into the prepared baking dish and spread it evenly.
In a separate bowl, combine the flour, oats, brown sugar, granulated sugar, cinnamon, and salt.
Add the cold, cubed butter to the bowl.
Use your fingertips or a pastry cutter to work the butter into the dry ingredients until the mixture forms coarse crumbs with some pea-sized bits.
If desired, mix in the chopped nuts for extra crunch.
Evenly sprinkle the crumble topping over the apple filling without pressing it down.
Place the dish on the middle oven rack and bake for 40–45 minutes, or until the topping is golden brown and the apple filling is bubbling around the edges.
Remove the crumble from the oven and let it cool for 10–15 minutes before serving.
Serve warm with vanilla ice cream, whipped cream, or caramel drizzle if desired.