Preheat oven according to box brownie mix instructions. (my mix said 325 degrees)
Line a 8 X 8 square baking pan with parchment paper, leaving an overhang for easier removal from pan.
Prepare brownie mix as per directions on the box.
Add ½ cup of chocolate chips (if not already included in mix)
Remove 1 cup of the brownie batter. Add the black cocoa powder and mix until fully combined. Set aside.
In a small bowl, combine cream cheese, sugar and vanilla. Beat or mix vigorously with a whisk.
Pour the original brownie batter into the prepared pan.
Add spoonfuls of the black cocoa batter and cream cheese mixture on top of the brownie mix.
Use a knife to swirl the batters together. Do not over swirl. A couple of passes in each direction is plenty.
Bake according to mix instructions. (usually 45-50 minutes)
Don't over bake...brownies continue baking in the pan as they cool.
