1. Preheat oven to 350°F (175°C) and line a 9×13-inch baking dish with parchment paper, leaving an overhang for easy removal.

2. In a bowl, combine graham cracker crumbs, melted butter, granulated sugar, and salt, then press firmly into the bottom of the prepared pan to form the crust.

3. Bake the crust for 8–10 minutes until lightly golden, then remove and let cool slightly.

4. In a large bowl, beat softened cream cheese with sugar until smooth, then add eggs one at a time, vanilla extract, and sour cream, mixing until just combined.

5. Pour the cheesecake filling over the cooled crust and smooth the top with a spatula.

6. In a separate bowl, toss sliced apples with brown sugar, cinnamon, nutmeg, and lemon juice until evenly coated.

7. Arrange the apple slices in a single layer over the cheesecake filling.

8. Bake the assembled bars for 35–40 minutes until the edges are set and the center is slightly jiggly, then remove and cool to room temperature.

9. Cover the pan and refrigerate for at least 4 hours or overnight to allow layers to firm up.

10. Using the parchment overhang, lift the chilled slab from the pan and place on a cutting board.

11. Drizzle caramel sauce over the top, sprinkle with flaky sea salt if desired, and use a sharp knife dipped in hot water to cut into neat squares.

12. Serve immediately or keep refrigerated until ready to enjoy; bars taste best after sitting at room temperature for 10 minutes.