Preheat the oven to 325°F. Spray a 9-inch springform pan with nonstick cooking spray.

In a large bowl, combine the butter, sugar, cocoa powder, and salt. Stir until well combined. Let cool if the butter is still hot. Stir in the vanilla and then the eggs, one at a time, stirring very well after each addition. Add the flour and stir again until combined. Spread into prepared pan.

Bake for 15 minutes, or until just starting to set. Let cool to room temperature, then chill in the fridge while you make the other layers.

In the bowl of an electric mixer, beat the cream cheese until smooth. Add the sugars and cream, and beat until well combined. Scrape down the sides and bottom of the bowl. Add the eggs, one at a time, beating just until smooth. Add the vanilla.

Pour the batter on top of the cooled brownie crust. Tap the pan on the counter to remove any air bubbles. Place the pan on a rimmed baking sheet and bake for about 55 minutes to 1 hour, until the top looks slightly dry. Allow to cool in the oven for 10 minutes.

Remove the cheesecake from the oven to cool completely to room temperature. Refrigerate until completely chilled, at least 4 hours or overnight.

Release the cheesecake from the pan onto a cake stand or serving plate. Cut into slices and drizzle each slice with caramel sauce. Serve.