Grease an 8x8" square pan.
Preheat oven to 325.
Make brownie batter according to box directions.
Pour batter into prepared pan.
Beat cream cheese until smooth.
Beat in egg and sugar until blended.
Using a spoon, drop dollops of mixture on top of brownies.
Drag a butter knife or spatula back and forth across length and width of pan to make swirls.
Bake for 40 minutes then tent top with aluminium foil.
Bake for additional 10-15 minutes or until toothpick inserted in middle comes out nearly clean.