I made these brownies recently and they were a hit.
1 package (21 oz.) dark brownie mix; prepare batter according to directions
2 8-oz. packages cream cheese, softened
2 large eggs
2 tablespoons sugar
2 teaspoons vanilla extract
Preheat the oven to 350 degrees.
Coat a 9" x 13" baking pan with nonstick cooking spray (Next time I will add parchment paper to the bottom).
Pour half of the brownie batter into the baking pan.
In a medium-sized bowl, with an electric beater on medium speed, combine the cream cheese, eggs, sugar, and vanilla until fluffy.
Spoon over the brownie batter, then top with the remaining half of the brownie batter.
Take a knife and swirl through the batter to create a marbled effect.
Bake for 35 to 40 minutes, or until a wooden toothpick inserted in the center comes out clean.
Cool, cut into bars and serve.