Cosi is awesome. Its a chic cafe. One of the items on the menu are s'mores. They bring a flame to your table along with marshmalllows, chocolate, and graham crackers. They have awesome sandwhiches, and great iced coffee drinks. And they serve alcohol! There are several in the Dupont Circle area
here is a link to their site so you can check it out.
http://www.xandocosi.com/