Preheat oven to 350°. Grease a 9 x 13" baking pan.

Make the brownie mix as directed and pour into pan. Beat the cream cheese, eggs, sugar and vanilla with an electric mixer in a separate bowl until well combined. Drop the cream cheese mixture by tablespoons on top of the brownie mixture. Swirl the mixture together with the end of a knife. Sprinkle the chocolate chips over the entire mixture.

Bake for 20-30 minutes or until cream cheese is slightly golden. Let cool for 20 minutes. Place in the refrigerator for 1 hour to chill before cutting into squares.