Directions

1. Preheat the oven to 375 degrees F (190 degrees C). Grease and flour a 10x15 inch jellyroll pan.
2. In a medium saucepan over medium-high heat, combine margarine, water and cocoa. Bring to a boil, and remove from heat. Combine the flour and 2 cups sugar; stir into the cocoa mixture until well blended, then stir in the eggs, sour cream, baking soda and salt. Spread evenly into the prepared pan.
3. In a small bowl, beat the cream cheese and 1/3 cup sugar until smooth. Spoon the cream cheese mixture over the batter in the pan. Swirl with a knife for a marbled effect. Sprinkle with chocolate chips.
4. Bake for 25 to 30 minutes in the preheated oven, until brownies start to pull away from the sides. Cool and cut into bars.