Preheat oven to 350 degrees.
Lightly spray a 9x9 baking dish with nonstick cooking spray or line with parchment paper.
Whisk the melted butter with the sugar in a large mixing bowl.
Blend in vanilla and then stir in flour, cornstarch, orange zest, white chocolate chips and cranberries. Stir just until everything is combined and the orange zest, white chocolate chips and cranberries are evenly distributed. Don't over mix the dough.
Pat the dough into the pan with your hands, making sure it is an even layer of dough.
Bake for about 25 minutes. The top will look pale, but the dough will be just beginning to turn golden around the edges.
Cool on a rack for about 15 minutes before cutting into squares.
To add topping: Combine softened cream cheese, powdered sugar and orange juice until smooth. Drizzle onto cooled squares. It will take about 20 minutes for the frosting and chocolate to set.