Preheat the oven to 325°F (160°C).

Prepare the crust by mixing graham cracker crumbs, melted butter, and sugar in a bowl.

Press the mixture into the bottom of a 9-inch springform pan evenly.

Bake the crust for about 10 minutes, until lightly golden.

In a large bowl, beat together the softened cream cheese and granulated sugar until smooth.

Add in the vanilla extract and mix until combined, then add the eggs one at a time, mixing well after each addition.

Pour the cheesecake mixture over the baked crust in the springform pan.

In a separate bowl, toss the sliced apples with cinnamon and brown sugar until evenly coated.

Layer the apple mixture over the cheesecake filling and gently press them down.

Prepare the crumble topping by mixing oats, flour, sugar, butter, salt, and nuts in a bowl until crumbly.

Sprinkle the crumble topping evenly over the apples.

Bake for 55-60 minutes or until the center is set and the top is golden.

Let it cool to room temperature, then refrigerate for at least four hours before serving.

Once chilled, carefully remove the springform pan and slice to serve.