I love these and a big fan of the thin chocolate mint Girl Scout cookies. The dense base layer is like a rich, fudgy brownie, so don't overcook it or the dessert bars will be dry. Refrigerating the mint bars allows the chocolaty top layer to set properly. If I make the dessert up to one day ahead. For a more grown-up taste, and can also use dark chocolate chips for some or all of the semisweet chocolate chips in the glaze.