Preheat the Oven: Set your oven to 325°F (163°C). Grease or line an 8-inch springform pan with parchment paper.

Make the Brownie Layer: In a mixing bowl, blend together melted butter and sugar until smooth. Mix in the eggs and vanilla extract until well combined.

Combine Dry Ingredients: In a separate bowl, whisk together cocoa powder, flour, salt, and baking powder. Slowly add this dry mix into your wet ingredients, stirring until just combined.

Bake the Brownie: Spread the brownie batter evenly into the prepared pan and bake for 15 minutes; the center will still be soft.

Prepare the Cheesecake Layer: Using another mixing bowl, beat the cream cheese and 1/2 cup granulated sugar until creamy. Add eggs one at a time, mixing well after each addition. Incorporate the vanilla and sour cream, mixing until fully combined.

Combine Layers: Pour the cheesecake mixture over the slightly baked brownie layer, making sure it’s evenly spread.

Final Bake: Return the pan to the oven and bake for 40-45 minutes; the center should be set but a bit wobbly when done.

Cool: Remove the cheesecake from the oven, let it cool completely at room temperature, then refrigerate for at least 4 hours or overnight.

Serve: Warm the hot fudge sauce and drizzle generously over the chilled cheesecake.

Garnish: Finish with a scoop of vanilla ice cream, a dollop of whipped cream, and any optional nuts or cherries.