Boxed brownie mix is a staple, and there are ways to hack it to make more gourmet creations. Transform it by turning it into a crust for a dessert pizza or adding it to rice-cereal treats.
Pour batter into prepared pan. Bake brownie until puffed and set and a tester inserted into the center comes out clean, 22 to 28 minutes. Let cool completely in pan. Using foil overhang ...