Preheat your oven to 325°F. This is the perfect temperature for a slow, even bake that gives you a creamy cheesecake instead of a cracked one.
Make your apple pie filling. In a medium saucepan over medium heat, melt 2 tablespoons of butter. Add the light brown sugar and cinnamon, stirring until combined. Add your diced apples and sauté for about 10 minutes, stirring occasionally, until the apples are just tender and starting to break down slightly. Sprinkle the cornstarch over top, stir well, and cook for 1 more minute until everything thickens up and looks glossy. Set this aside to cool completely - you need it room temperature or cooler before you spread it on your crust.
Make your crust. In a bowl, combine graham cracker crumbs, melted butter, and brown sugar until it looks like wet sand. Press firmly into the bottom of your 9-inch springform pan, making sure it's even and packed down. Bake for 10 minutes until lightly golden, then set aside to cool slightly.
Make the crumble topping. In a bowl, mix together melted butter, flour, brown sugar, and cinnamon until the mixture resembles wet sand.
Now for the cheesecake filling. In a large bowl, beat room temperature cream cheese for 2-3 minutes until completely smooth. Add the sour cream and sugar and beat for another minute. Add the eggs one at a time, beating well after each, then stir in the vanilla until just combined.
Pour the cheesecake filling slowly and carefully over the graham cracker pie crust, smoothing it out gently with a spatula to make an even layer.
Spread the cooled apple filling evenly over the cheesecake.
Spread the crumble topping evenly over the apple pie filling. Make sure you get it all the way to the edges so it bakes evenly.
Optional step, but highly recommended (water bath):Seal the bottom of springform pan in aluminum foil. I like to use two 12 inch sheets to make sure it is full sealed. Add 1/2 inch of water to a baking sheet. Place the cheesecake in the center of the water. Bake for 55-65 minutes. The cheesecake is done when the edges are set but the center still jiggles slightly when you gently shake the pan - about a 2-inch circle in the very middle should still wobble. This is what gives you that creamy, perfect texture.
Turn the oven off and crack the door open about 4 inches. Let the cheesecake sit in the cooling oven for 1 hour - this helps it cool gradually and prevents cracking.
Remove from the oven and let it chill to room temperature on the counter for an additional hour then transfer it to the fridge for at least 3-4 hours, but honestly, overnight is better. The cold time is when the cheesecake sets up perfectly.
Before serving, drizzle generously with salted caramel sauce and maybe even add a little extra sprinkle of cinnamon. Slice with a hot, wet knife (dip it in hot water and wipe it clean between slices) for clean, beautiful cuts.