Prepare the Brownie Base

1. Preheat the Oven: Set your oven to 350°F (175°C). Grease a 9-inch springform pan and line the bottom with parchment paper.
2. Mix the Batter: In a mixing bowl, whisk together melted butter, sugar, eggs, and vanilla until smooth.
3. Add Dry Ingredients: Sift in the cocoa powder, flour, salt, and baking powder. Stir until just combined.
4. Bake: Pour the batter into the prepared pan and spread evenly. Bake for 15 minutes, then remove from the oven. The brownie layer should be slightly set but not fully baked.

Prepare the Cheesecake Layer

1. Beat the Cream Cheese: In a large bowl, beat the cream cheese until smooth and creamy.
2. Add Sugar and Eggs: Mix in the sugar, then beat in the eggs one at a time until fully incorporated.
3. Stir in Vanilla and Sour Cream: Gently mix in vanilla and sour cream until smooth.
4. Layer on the Brownie Base: Pour the cheesecake batter over the partially baked brownie layer, spreading it evenly.
5. Bake Again: Return the pan to the oven and bake for 35-40 minutes, or until the center is just set and slightly jiggly.

Cool and Chill

1. Cool in the Pan: Remove the cheesecake from the oven and allow it to cool at room temperature for 1 hour.
2. Refrigerate: Cover and chill in the refrigerator for at least 4 hours, preferably overnight, to set completely.

Add the Caramel Topping

1. Drizzle with Caramel: Before serving, drizzle caramel sauce generously over the cheesecake.
2. Optional Sea Salt: For a salted caramel touch, sprinkle a pinch of sea salt over the top.