La Charlotte de l'Isle has been serving teas and hot chocolates accompanied by homemade cakes and tarts for over thirty years. Be thankful you can only indulge from Thursday through Sunday!

My absolutely favorite place for hot chocolate is La Charlotte de l'Îsle, a cluttered, almost alarmingly charming little cafe on the Île St-Louis run by a flamboyant woman of a certain age who could probably tell great stories of la vie de bohème after a carafe or two of wine. Rich, bittersweet, dreamily good, hers is the absinthe of hot chocolate."
The New York Times, 12/12/2004.

http://perso.orange.fr/la-charlotte/salon/salon.htm