Preheat your oven to 160ºC (325ºF). In a food processor, combine digestive or graham crackers, ground nutmeg, ground cinnamon, dark brown sugar, and melted butter until the mixture resembles wet sand. Press this mixture firmly into the bottom of a 22 cm (9 in) springform pan. Bake for 10 minutes until just set, then remove and let it cool completely.

Dice your apples into small cubes and place them in a bowl. Sprinkle granulated sugar and ground cinnamon over the apples, tossing gently to combine. Set aside to allow the flavors to meld.

In a medium bowl, combine all-purpose flour, brown sugar, and room temperature butter. Using your fingers or a pastry cutter, mix these ingredients until they form a crumbly texture. Set this crumble mixture aside along with your prepared spiced apples.

In a large mixing bowl, beat the cream cheese until smooth. Gradually incorporate granulated sugar into the cream cheese, mixing well after each addition. In a separate bowl, mix sour cream with cornstarch until smooth, then add this to the batter. Add eggs one at a time, ensuring each egg is fully incorporated before adding the next.

Pour the cheesecake batter into the cooled crust, spreading it evenly with a spatula. Gently layer the prepared apples over the batter, then sprinkle the crumble mixture generously on top.

Place the springform pan inside a larger baking pan. Pour hot water into the larger pan to create a water bath, which helps the cheesecake bake evenly. Bake for 1 hour and 20-30 minutes until the center is slightly wobbly.

Once baked, turn off the oven and leave the cheesecake inside for 1 hour with the door slightly ajar. Transfer the cheesecake to a cooling rack. Once cooled, refrigerate for at least 6 hours, preferably overnight.