Chelsea Market has a little shop called Fat Witch Brownies. If the name doesn't tempt you maybe their website will. http://www.fatwitch.com/index.html
I can attest that their variety of brownies are quite yummy and work very nicely as hostess gifts. Particular favorites are the Blonde Witch (Fat Witch's version of a blondie), Snow Witch (white chocolate brownie), Caramel Witch, and the cute little Fat Witch Baby. Thick, rich, fudgy, and you can get them fresh in Chelsea... or order them sent to your home- they travel well.