Preheat the oven to 350 degrees F (180 degrees C) and spray an 8 x 8 baking dish really well with Nonstick Cooking Spray (as needed).
Mix the Strawberry Cake Mix (1 box), Mascarpone Cheese (1/2 cup), Canola Oil (1/3 cup), Egg (1) and Balsamic Vinegar (1/2 teaspoon) together in a large mixing bowl. You can use your hands or an electric mixer. It will be extremely thick and sticky, almost like silly putty.
Press the batter into an even layer in the prepared pan and bake it for 30-35 minutes, until golden around the edges and completely set in the center.
When the brownies are finished baking, let them cool for at least 30 minutes.
While they cool, melt the Semi-Sweet Chocolate Chips (1/3 cup) in the microwave in 30 second increments until they are completely melted, stirring after each time you microwave them.
Drizzle the melted chocolate over the cooled brownies in thick stripes.
Then let them cool completely and the chocolate harden. You can even chill them in the refrigerator a little to speed this up.
Cut them into 16 equal squares and serve! These keep for a couple of days too in a sealed container. Enjoy!