Preheat your oven to 350°F (175°C) and line a square baking pan with parchment paper, ensuring there's an overhang for easy removal.

In a microwave-safe bowl, melt the butter and chopped dark chocolate together, stirring every 20 seconds until glossy.

Whisk the sugar into the melted chocolate mixture until dissolved. Add the eggs one at a time, whisking briskly after each addition, then stir in the vanilla extract.

Gently fold the sifted flour into the wet ingredients using a spatula, mixing until just combined.

Beat the softened cream cheese until smooth, then gradually add the sugar, the egg, and vanilla extract, mixing until just combined.

Pour half of the brownie batter into the prepared pan. Dollop the cheesecake mixture over it and spoon the remaining brownie batter on top, swirling with a knife.

Bake for 40–45 minutes, looking for edges that are set and a slightly jiggly center.

Heat the heavy cream until simmering. Pour it over the chopped dark chocolate, let it sit for a minute, then stir until smooth.

Once the brownies are cool, pour the ganache over the top, chill until set, and cut into squares to reveal the layers.