01 - Preheat oven to 350°F. Line the bottom of a 9-inch springform pan with parchment paper and lightly grease the sides.
02 - In a mixing bowl, blend graham cracker crumbs, melted butter, granulated sugar, and cinnamon until evenly combined. Press mixture firmly into the base of the prepared pan. Bake for 10 minutes, then set aside to cool.
03 - In a skillet over medium heat, melt butter. Add the diced apples, brown sugar, cinnamon, nutmeg, and salt. Cook, stirring occasionally, for 5 to 7 minutes until apples are softened. Pour in bourbon and cook for 1 additional minute. Remove skillet from heat and let apples cool. Reserve one-third of apples for topping.
04 - In a large bowl using an electric or stand mixer, beat softened cream cheese with granulated sugar until smooth. Incorporate eggs one at a time, mixing after each addition. Blend in sour cream, flour, vanilla extract, and bourbon just until combined.
05 - Gently fold the remaining two-thirds of cooled spiced apples into the cheesecake batter. Pour mixture over the baked crust, smoothing the top evenly.
06 - Bake cheesecake at 350°F for 55 to 60 minutes, until edges are firm and center remains slightly jiggly. Turn off the oven, crack the door, and let cheesecake rest for 1 hour inside.
07 - Transfer cheesecake to room temperature and allow it to cool completely. Refrigerate the cooled cheesecake for at least 4 hours or overnight to set.
08 - Before serving, top cheesecake with reserved spiced apples and, if desired, garnish with whipped cream or drizzle with caramel sauce.