01 -
Preheat oven to 175°C. Line a 23 cm x 23 cm square pan with foil and lightly grease with nonstick cooking spray.
02 -
Combine baking chocolate and unsalted butter in a large microwave-safe bowl. Heat in 30-second intervals, stirring between each, until fully melted and smooth, approximately 2 minutes.
03 -
Add granulated sugar and cocoa powder to the chocolate-butter mixture. Mix with a spatula or wooden spoon. Beat in eggs and vanilla extract followed by salt, stirring until the batter is smooth yet grainy. Carefully fold in the flour until just combined.
04 -
Transfer the brownie batter into the prepared pan, spreading evenly, and set aside.
05 -
In a separate bowl, beat cream cheese with sour cream until completely smooth. Incorporate eggs, granulated sugar, and vanilla extract, mixing until evenly blended.
06 -
Pour cheesecake mixture over the brownie batter in the pan. Utilize a butter knife or long skewer to create a marbled swirl pattern across the surface.
07 -
Bake in the preheated oven for 50 to 55 minutes, or until the top is slightly puffed, the surface is no longer glossy, and the edges are light golden. Remove from oven and allow to cool completely at room temperature.
08 -
Refrigerate for a minimum of 4 hours before slicing into squares. Serve chilled.
09 -
Store in an airtight container in the refrigerator for up to 3 days or freeze for up to 3 months.