Prepare the brownie base by mixing graham cracker crumbs, cocoa powder, granulated sugar, and melted butter. Press into the bottom of a 9-inch springform pan.

Make the cheesecake filling by beating cream cheese and sugar until smooth. Add eggs one at a time, then stir in vanilla extract and sour cream. Fold in chocolate chips.

Combine brownie and cheesecake layers by pouring half of the cheesecake mixture over the crust, drizzling with half of the caramel sauce, then adding the remaining cheesecake mixture and caramel.

Bake at 325°F for 50-60 minutes until edges are set and center is slightly jiggly. Turn off oven and let cool inside for 1 hour.

Cool to room temperature, then refrigerate for at least 4 hours or overnight before serving.