Preheat your oven to 325°F (160°C) and grease a 9-inch springform pan.

In a large bowl, combine melted butter and sugar. Add eggs, one at a time, mixing well after each addition.

Stir in vanilla, then mix in cocoa powder, flour, salt, and baking powder until well combined.

Pour the brownie batter into the prepared pan and spread evenly.

In another bowl, beat the softened cream cheese and sugar until smooth.

Add the eggs, one at a time, followed by vanilla and flour. Mix until just combined and creamy.

Pour the cheesecake batter over the brownie base in the springform pan, smoothing out the top with a spatula.

Place the pan in the preheated oven and bake for about 50 minutes, until the cheesecake is set but still slightly jiggly in the center.

Allow the dessert to cool at room temperature for about an hour, then cover and refrigerate for at least four hours, or overnight before serving.

Carefully release the cheesecake from the springform pan. Slice into pieces and serve with your favorite toppings!