Flick the oven onto 200°c bake and line a 20cm square tin with baking paper and set aside.
Melt together the butter and white chocolate in a medium saucepan, then allow to cool slightly.
In a medium sized bowl, beat together the cream cheese ingredients with a hand-held mixer then set aside while you continue with the brownie batter.
When butter and chocolate mixture have cooled, beat through the sugar and eggs, vinegar and red colour gel until glossy. Sift in the flour, baking powder, cocoa and salt and fold through until smooth and incorporated. Don't over mix.
Pour 3/4 of the brownie mixture into the prepared baking tin. Gently spread the cream cheese mixture over top before dolloping the remaining brownie mixture over top of the cream cheese layer. Using a skewer or tip of a knife, swirl the brownie mixture to create a pattern.
Bake brownie for around 23-25 minutes or until the top has set. From the oven, place the baking tin straight in the fridge to stop further baking.
When cooled, slice and enjoy!