Start by crushing the Biscoff cookies into fine crumbs, using a food processor or a rolling pin. In a bowl, combine the crumbs with melted unsalted butter until the mixture resembles damp sand. Press this mixture firmly into the bottom and about 1 inch up the sides of a 9-inch springform pan. For the best results, chill the crust in the fridge for at least 30 minutes to set.

In a medium bowl, mix melted butter, all-purpose flour, brown sugar, and rolled oats until the mixture forms crumbly clumps. Set aside for about 15 minutes to firm up.

Over medium heat, sauté sliced tart apples in a skillet with a touch of brown sugar and ground cinnamon until tender and syrupy, about 5-7 minutes. Set the apples aside to cool.

Preheat your oven to 325°F (165°C). Prepare for baking by placing a sheet pan on the bottom rack.

In a large mixing bowl, beat softened cream cheese with granulated sugar, Greek yogurt, vanilla extract, and spices until smooth. Incorporate the eggs one at a time, avoiding overmixing.

Pour the cheesecake filling over the chilled Biscoff crust, smoothing it out. Arrange the cooked apples on top, then sprinkle the crumble topping evenly across.

Bake for 65-70 minutes. The edges should be firm while the center remains slightly jiggly.

Allow the cheesecake to cool at room temperature for about 1 hour, then refrigerate for at least 6 hours, preferably overnight.