Preheat your oven to 350°F (175°C). In a large bowl, mix the graham cracker crumbs, melted butter, and granulated sugar together until evenly combined.

Press the mixture firmly into the bottom of a 9-inch springform pan. Bake for 10 minutes, then set aside to cool.

In a separate large bowl, beat the softened cream cheese until smooth and free of lumps.

Add the granulated sugar and vanilla extract, mixing until well combined.

Add the eggs one at a time, mixing on low speed and scraping down the sides of the bowl after each addition.

Finally, fold in the sour cream until well incorporated.

In a medium bowl, toss the diced apples with brown sugar, cinnamon, cornstarch, water, and lemon juice. Set aside to allow the apples to release some moisture.

Pour the cheesecake filling over the cooled crust and smooth the top with a spatula.

Gently spoon the prepared apple mixture on top of the cheesecake layer.

In a medium bowl, mix together all-purpose flour, brown sugar, and cinnamon.

Use your fingers to cut in the cold butter until the mixture resembles coarse crumbs.

Sprinkle this mixture over the apples.

Place the springform pan in the preheated oven and bake for about 60-70 minutes, or until the center is set but slightly wobbly.

To prevent cracks, you may place a water bath in the oven.

After baking, allow the cheesecake to cool at room temperature for about an hour, then refrigerate it for at least four hours before serving.