1. Preheat oven to 325°F (163°C). Prepare a springform pan by greasing it and lining the bottom with parchment paper.

2. Mix graham cracker crumbs with ¼ cup melted butter. Press mixture into the bottom of the pan to form the crust. Bake for 10 minutes, then cool.

3. In a large bowl, beat cream cheese until smooth. Add granulated sugar and beat until fluffy. Mix in eggs one at a time, followed by sour cream and vanilla extract. Pour mixture over the cooled crust.

4. In a skillet over medium heat, cook diced apples with 2 tablespoons of butter, cinnamon, nutmeg, and 2 tablespoons of sugar until slightly softened (about 5–7 minutes). Let cool.

5. In a separate bowl, mix oats, flour, brown sugar, and pecans. Add remaining melted butter and stir until crumbly.

6. Layer cooked apples evenly over the cheesecake batter. Sprinkle the oat-pecan crumble on top.

7. Bake for 55–65 minutes or until edges are set and the center slightly jiggles. Turn off oven and crack the door; let cheesecake rest for 1 hour inside.

8. Refrigerate for at least 4 hours or overnight.

9. Before serving, drizzle caramel sauce on top and garnish with whipped cream if desired.