Preheat your oven to 160ºC (325ºF). Blend digestive or graham crackers, dark brown sugar, ground cinnamon, and nutmeg in a food processor until finely crushed. Add melted butter and pulse until it resembles wet sand. Press mixture into a prepared springform pan. Bake for about 10 minutes until lightly golden, then let cool completely.

Dice apples into small pieces, toss with granulated sugar and ground cinnamon. Mix all-purpose flour, granulated sugar, and room-temperature butter in a bowl for crumble topping until crumbly. Set aside.

In a large mixing bowl, beat cream cheese until smooth. Gradually add granulated sugar and mix in sour cream and cornstarch. Add eggs one at a time, mixing on low speed until blended.

Once crust has cooled, pour cheesecake filling into crust. Distribute cinnamon sugar apples over the filling and sprinkle crumble topping on top.

Place springform pan in a larger cake pan filled with hot water halfway up the sides. Bake for 80-90 minutes until edges are set but center is slightly jiggly.

Leave cheesecake in oven with the door cracked for an hour to cool. Carefully remove from water bath and let cool to room temperature. Refrigerate for at least 6 hours or overnight before serving.