Preheat your oven to 350°F (175°C) and grease a 9-inch springform pan. In a mixing bowl, whisk together the melted unsalted butter, granulated sugar, and Dutch-processed cocoa powder until well combined. Add in two large room-temperature eggs and a tablespoon of vanilla extract, mixing until smooth. Gradually fold in half a cup of all-purpose flour and a pinch of salt. Pour this mixture into the prepared pan and bake for 15-18 minutes.

Lower the oven temperature to 325°F (160°C). In a large mixing bowl, beat the cream cheese with the granulated sugar until creamy. Mix in the sour cream and remaining vanilla extract. Add the eggs one at a time, blending on low speed. Pour the cheesecake filling over the warm brownie base.

Place the springform pan inside a larger roasting pan and add hot water until it reaches halfway up the sides. Bake for 50-60 minutes, until the edges are firm but the center jiggles slightly. Turn off the oven, let cool inside for one hour.

In a saucepan, combine the heavy cream, corn syrup, and chopped dark chocolate over medium heat. Stir continuously until heated and the chocolate is melted, then let cool slightly.

Once the cheesecake has chilled, remove it from the pan. Pour the hot fudge sauce over the top, allowing it to cascade down the sides. Top with whipped cream, chopped peanuts, and maraschino cherries. Slice and serve.