Roll the cookie dough out into a large rectangle.Bake according to the directions on the package.
Meanwhile, prepare the cheesecake topping by combining the cream cheese, mascarpone, milk, vanilla, and powdered sugar in the bowl of an electric mixer. Mix on a medium speed, stopping to scrape down the sides of the bowl as necessary. Mix for 1 minute, until the mixture is smooth. Set aside.
Once the cookie dough has baked, use a pizza cutter to slice the cookie into smaller rectangular cookies about 3x4 inches in size.
Spread a layer of the cheesecake topping over the cookies. Then decorate with blueberries and strawberries. I cut the strawberries into thin strips so that I could use them to make the stripes for the flag.
Serve within a hour so that the cheesecake topping doesn't cause the cookie to become soggy.