Prepare the crust: Preheat the oven to 325°F (163°C). Grease and line the bottom of a 9-inch springform pan with parchment paper. Combine Biscoff cookie crumbs, sugar, and melted butter, then press into the pan. Bake for 8-10 minutes, then cool.
- Prepare the filling: Beat softened cream cheese, sugar, and vanilla extract until smooth. Add eggs, one at a time, mixing well after each addition. Stir in sour cream, heavy cream, flour, and salt until combined.
- Bake the cheesecake: Pour the filling into the cooled crust and smooth the top. Bake for 55-60 minutes, or until the edges are set and the center is slightly jiggly. Turn off the oven and cool for 1 hour, then refrigerate for at least 4 hours, or overnight.
- Prepare the topping: Drizzle caramel sauce and melted chocolate over the chilled cheesecake. Sprinkle with toasted pecans and garnish with whipped cream, if desired.
- Serve: Carefully remove the cheesecake from the springform pan and transfer to a serving platter. Slice and serve chilled.