My 17 yr. old brother wants me to make his birthday dessert -- no cake, just cream cheese brownies. He is content with the mix from the store, but I refuse to use the mix (you know, the kind with the powdered cream cheese -- yuk). Does anyone have a tried and true recipe for cream cheese brownies (thick and moist and chewy)-- preferably in a 9x13 pan?? Please pass it along if you do. thanks!