preheat oven at 375

grease pan 13 "×9", cooking spray,

make brownies as directed on box using water ,oil and eggs, pour half of batter into pan,

in a small bowl, , stir remaining ingredients except powder sugar until smooth.

dropped cheese mixture by spoonful onto brownie batter, pour the remaining brownie batter over cheese mixture,

swirl cheese mixture through brownie batter with a knife for marble design,

bake for30 to 35 minutes, or until toothpick inserted ,two inches from the side of pan and comes out clean.

cool

when cooled down sprinkle with powder sugar if the desired.