Follow these simple steps to create your Creamy Brownie Cheesecake:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Prepare a 9-inch springform pan by greasing it with butter or cooking spray.
2. Make the Brownie Layer:
– In a saucepan, melt the butter over low heat.
– Remove from heat and stir in the sugar.
– Mix in the eggs and vanilla until well combined.
– In a separate bowl, mix together cocoa powder, flour, baking powder, and salt. Gradually add this mixture to the wet ingredients, stirring until just combined.
3. Bake the Brownie Layer: Pour the brownie batter into the bottom of the prepared springform pan. Spread it evenly and bake for 20-25 minutes until set but still fudgy. Let it cool slightly while you prepare the cheesecake.
4. Prepare the Cheesecake Layer:
– In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth.
– Gradually add the sugar, mixing until combined.
– Add the eggs one at a time, mixing on low speed after each addition until just combined.
– Stir in the vanilla extract and sour cream, if using.
5. Assemble Layers: Pour the cheesecake mixture over the cooled brownie layer in the springform pan. Smooth out the top with a spatula.
6. Bake the Cheesecake: Bake the cheesecake for 40-45 minutes, or until the center is set and a slight jiggle remains.
7. Cool: Turn off the oven and crack the door open. Allow the cheesecake to cool in the oven for about an hour. Afterward, let it cool to room temperature before refrigerating for at least 4 hours, or overnight for best results.
8. Release and Serve: Carefully run a knife around the edges of the springform pan to release the cheesecake. Remove the sides of the pan and transfer the cheesecake to a serving plate.

By following these detailed steps, you’ll create a stunning and delectable Creamy Brownie Cheesecake that’s sure to impress!