Preheat your oven to 350°F (175°C). Combine graham cracker crumbs, granulated sugar, optional cinnamon, melted unsalted butter, and a pinch of salt in a mixing bowl. Press into the bottom of a springform pan and bake for 8–10 minutes until golden. Let it cool.

In a saucepan, combine granulated sugar and water and cook until amber, about 6–8 minutes. Remove from heat, whisk in heavy cream and unsalted butter until smooth, then stir in vanilla extract and flaky sea salt.

Melt unsalted butter in a skillet, add diced apples, light brown sugar, ground cinnamon, ground nutmeg, and a pinch of salt. Cook for 8–10 minutes until softened, then stir in fresh lemon juice and cornstarch slurry to thicken.

In a mixing bowl, beat cream cheese until smooth. Gradually add granulated sugar, then mix in sour cream, vanilla extract, and a pinch of salt. Incorporate eggs one at a time, mixing gently.

Lower oven temperature to 325°F (160°C). Pour reserved cooled salted caramel over crust, layer cheesecake filling, and bake in a water bath for about 60–75 minutes. Cool for 1 hour before refrigerating for 6–8 hours.

Remove cheesecake from the refrigerator, top with cooled apple filling, drizzle with reserved salted caramel, and garnish as desired. Slice and serve.