Preheat the oven to 350°F (175°C).
In a mixing bowl, combine graham cracker crumbs and melted butter.
Press the crumb mixture into the bottom of a springform pan to create an even layer.
In another bowl, beat the cream cheese, sugar, and vanilla until smooth.
Add the eggs one at a time, mixing until just combined after each addition.
Pour the cream cheese filling onto the prepared crust and smooth the top.
In a separate bowl, mix diced apples with cinnamon and brown sugar.
Spread the apple mixture over the cream cheese layer.
In a small bowl, combine oats, flour, and additional brown sugar to make the crumble topping.
Add melted butter to the crumble mixture and mix until crumbly.
Sprinkle the crumble evenly over the apple layer.
Bake in the preheated oven for 50-60 minutes, or until set.
Allow the cheesecake to cool and then refrigerate for at least 4 hours before serving.
Run a knife around the edges before releasing the springform pan.
