Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan and line the bottom with parchment paper.,For the crust, combine the crushed Biscoff cookies, sugar, and melted butter in a medium bowl. Press the mixture into the bottom of the prepared pan, creating an even layer. Bake for 10 minutes, then remove and let it cool.,For the cheesecake filling, beat the softened cream cheese and Biscoff cookie butter together in a large mixing bowl until smooth and creamy.,Add the sugar, eggs, and vanilla extract, and beat until fully combined.,Add the sour cream and heavy cream, mixing until smooth and well-combined.,Pour the cheesecake filling over the cooled crust and smooth the top with a spatula.,Bake the cheesecake for 50-60 minutes, or until the center is set but still slightly jiggly. Turn off the oven and let the cheesecake cool in the oven with the door slightly ajar for 1 hour.,Remove the cheesecake from the oven and let it cool completely at room temperature. Once cooled, refrigerate for at least 4 hours, or overnight, to set.,Once ready to serve, drizzle the top with caramel sauce, sprinkle with crushed Biscoff cookies, and garnish with whipped cream if desired.