Preheat the oven to 325°F. Line an 8×8 square pan with aluminum foil or parchment paper, leaving some overhang. This will help you easily lift the bars out after baking.
Place the graham crackers in a food processor and pulse until they turn into fine crumbs. You want a sandy texture.
Add the graham cracker crumbs to a large mixing bowl. Then, combine them with the brown sugar and melted butter. Stir until everything is well mixed and the crumbs are moist.
Press the mixture firmly into the bottom of the prepared pan. Make sure it’s even and packed tightly. This will create a solid base for your bars.
Bake the crust in the preheated oven for 8 minutes. Then, let it cool for at least 5 minutes.
In a large mixing bowl, whip the cream cheese using an electric mixer until smooth, about 2 to 3 minutes. You want it to be creamy and free of lumps.
Add the sugar and mix until fully combined. It should be smoothly incorporated into the cream cheese.
Incorporate the lightly beaten eggs, one at a time, mixing well after each addition to maintain a smooth texture.
Next, add the sour cream and vanilla, whipping until everything is well blended and smooth.
In a separate bowl, mix together the rolled oats, brown sugar, flour, cinnamon, and melted butter until the oats are no longer dry. This is your crumble topping.
Peel the apple and dice it into very small pieces, about 1/4 inch cubes. This will help them distribute nicely in the bars.
Add the diced apples to a bowl, along with sugar, flour, and cinnamon. Mix until the apples are all coated.
Pour the cheesecake filling over the cooled graham cracker crust, spreading it evenly with a silicone spatula.
Top with the apple mixture, spreading it evenly across the cheesecake layer.
Use a chopstick or butter knife to swirl the apples into the cheesecake slightly for an even distribution.
Sprinkle the crumble topping over the apple layer evenly.
Bake the cheesecake bars in the oven at 325°F for 65 to 70 minutes. You want most of the moisture to be gone from the center.
Once baked, let them cool for 20 minutes in the pan, then transfer to the refrigerator and chill for at least 6 hours or overnight before serving.
Serve with a drizzle of caramel sauce over the top for an extra touch of indulgence!
