Preheat the oven to 350°F (175°C).
In a mixing bowl, combine graham cracker crumbs and melted butter.
Press the mixture firmly into the bottom of a round springform pan.
In a large mixing bowl, beat the softened cream cheese until smooth.
Add sugar, eggs, vanilla extract, and cinnamon; mix until well combined.
Fold in the sliced apples gently into the cheesecake batter.
Pour the apple-infused cheesecake batter over the graham cracker crust.
In a separate bowl, mix flour, brown sugar, oats, and additional melted butter for the crumble topping.
Sprinkle the crumble mixture evenly over the cheesecake batter.
Bake for 45-50 minutes or until the edges are set but the center is slightly jiggly.
Let the cheesecake cool in the pan before transferring to the refrigerator.
Slice and serve your delicious apple crumble cheesecake.