Preheat your oven to 325°F (160°C).

In a food processor, pulse the digestive biscuits or graham crackers with the cinnamon and sugar until they resemble fine crumbs. Drizzle in the melted butter and pulse until combined. Press this mixture firmly into the bottom of the prepared springform pan and set it aside.

Bake the crust for 10 minutes until slightly golden and firm around the edges. Let it cool completely.

In a small bowl, combine the dark brown sugar and some cinnamon, mixing until evenly combined. Set it aside.

In another bowl, whisk together the flour and remaining dark brown sugar. Pour in melted butter and mix until crumbly. Set aside.

In a stand mixer, beat the cream cheese until smooth, then gradually add the sugar, mixing until well blended.

In a separate bowl, mix sour cream with cornstarch, then add it to the cream cheese mixture and mix in vanilla extract. Incorporate the eggs one at a time, avoiding overmixing.

Pour half of the cheesecake batter onto the cooled crust, spreading evenly. Sprinkle half of the cinnamon sugar mixture over the batter, then pour the remaining cheesecake batter on top.

Evenly distribute the crumble mixture over the top of the cheesecake batter.

Place the springform pan in a larger baking dish filled with hot water and bake for 1 to 1½ hours, until the center is slightly wobbly.

Turn off the oven and leave the cheesecake inside with the door ajar for about an hour to cool. Then refrigerate for at least 6 hours, or overnight.

Release the cheesecake from the springform pan, slice into wedges, and serve chilled or at room temperature.