chocolate brunch @ hotel?
I'm not sure if this is what you're looking for, but I believe that the new Fauchon offers a chocolate tea. I could be wrong. Fauchon is on Park Avenue in upper 50s, possibly in Swisshotel. I took a little spin in Fauchon --one of Paris's hoitiest, toitiest food shops--and there's lots of wonderful pricey tea, biscuits, cookies, candy as well as a cute tearoom.
Let me know if it turns out that this is correct.