1: Preheat oven to 175°C / 350°F and grease and line an 8x8 inch pan with parchment paper.
2: Whisk cream cheese, egg, cornstarch, sour cream, vanilla, and sugar until smooth to prepare the Cream Cheese Layer.
3: Brown the butter in a saucepan, stirring until golden brown, then transfer to a bowl.
4: Mix in cocoa powder, oil, vanilla, and chopped chocolate until dissolved. Add vinegar and food color, then cool for 15-20 minutes.
5: Whisk eggs and light brown sugar until dissolved and pale in color before adding powdered sugar and mixing for 1-2 minutes.
6: Combine the egg mixture with the browned butter mixture, then add flour and chocolate chips, mixing until just combined.
7: Transfer half the brownie mixture to the pan, reserve a portion of the cream cheese mixture, and spread the remaining cream cheese mixture on top.
8: Add the remaining brownie batter over the cream cheese layer and swirl with reserved cream cheese mixture.
9: Bake for 35-40 minutes until the edges are golden and the center is slightly fudgy. Allow to cool completely before cutting.
