In a medium saucepan over medium-low heat, cook 1 cup of granulated sugar until it melts and turns a deep amber color, about 10 minutes. Remove from heat, and carefully whisk in 6 tablespoons of unsalted butter and 1/2 cup of heavy cream until smooth. Let the caramel cool for at least 15 minutes while you prepare other components.

Wrap the bottom and sides of a 9-inch springform pan with aluminum foil to prevent water from seeping in during baking.

Pulse 1 1/2 cups of graham crackers in a food processor until finely crushed. In a bowl, blend the crumbs with 1/4 cup melted unsalted butter and 1/4 cup granulated sugar, along with a teaspoon of cinnamon. Press the mixture firmly into the bottom of the springform pan, and bake at 350°F (175°C) for 10 minutes. Allow it to cool while you mix the filling.

In a large mixing bowl, beat 16 ounces of room temperature cream cheese and 1 cup of granulated sugar until creamy and smooth, about 3 minutes. Gradually add 1/4 cup of cornstarch, followed by 1 cup of sour cream, 1 teaspoon of vanilla, and a dash of cinnamon. Gently incorporate 3 large eggs and 2 egg yolks until just combined.

Pour the cheesecake filling into the cooled crust, smoothing the top with a spatula. Place the springform pan in a larger baking dish filled with hot water, creating a water bath. Bake at 325°F (160°C) for 1 hour. Turn off the oven and leave the door slightly ajar for an additional hour to cool gradually.

Peel and dice 2-3 firm apples, then toss them in a skillet with 1/4 cup of brown sugar, 1 teaspoon of cinnamon, and a pinch of salt. Cook over medium heat for about 20 minutes until soft and caramelized, then set aside to cool.

In a bowl, mix 1/2 cup of all-purpose flour, 1/2 cup of brown sugar, and 1/4 cup of melted butter until crumbly. Spread evenly on a baking sheet and bake at 350°F (175°C) for 10–15 minutes, or until golden brown. Let it cool while finishing the cheesecake assembly.

Once the cheesecake has cooled completely, drizzle the salted caramel sauce over the top, add the cooked apple mixture, and sprinkle the streusel topping. Chill the assembled cheesecake in the fridge for at least 4 hours or overnight for better slice integrity.