1. Prepare the Crust

1. Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan and line the bottom with parchment paper.
2. In a medium bowl, combine the graham cracker crumbs, sugar, and cinnamon. Add the melted butter and mix until the texture resembles wet sand.
3. Press the mixture firmly into the bottom of the prepared pan. Use the back of a spoon or the bottom of a glass to create an even layer. Bake for 8–10 minutes, then set aside to cool.

2. Make the Cheesecake Filling

1. In a large mixing bowl, beat the softened cream cheese and sugar with an electric mixer on medium speed until smooth and creamy, about 2–3 minutes.
2. Add the sour cream and vanilla extract, beating until well combined.
3. Beat in the eggs one at a time, mixing on low speed after each addition to avoid overbeating. Set the filling aside.

3. Prepare the Spiced Apple Layer

1. In a medium saucepan over medium heat, combine the diced apples, sugar, cinnamon, nutmeg, lemon juice, and cornstarch.
2. Cook for 5–7 minutes, stirring occasionally, until the apples are tender and the mixture has thickened. Remove from heat and let cool slightly.

4. Make the Crumble Topping

1. In a small bowl, mix together the flour, oats, brown sugar, and cinnamon. Add the cold butter and use your fingers or a pastry cutter to combine until the mixture forms coarse crumbs.

5. Assemble the Cheesecake

1. Pour the cheesecake filling over the cooled crust, spreading it into an even layer.
2. Spoon the spiced apple mixture over the cheesecake filling, distributing evenly.
3. Sprinkle the crumble topping over the apples.

6. Bake the Cheesecake

1. Place the springform pan on a baking sheet and bake in the preheated oven for 50–60 minutes, or until the center is set but still slightly jiggly.
2. Turn off the oven and crack the door open slightly, letting the cheesecake cool inside for 1 hour. This helps prevent cracks.

7. Chill and Serve

1. Once the cheesecake has cooled to room temperature, refrigerate it for at least 6 hours or overnight.
2. Run a knife around the edge of the pan before releasing the springform. Slice and serve with whipped cream or caramel sauce if desired.