The last time I was in New Orleans, this summer, Jack Sprat's was indeed closed.
It was one of my favorite restaurants, so I was sad to see it go. (Great, but
fat-full, desserts.) Another good place is Old Dog, New Trick. It's located in
the quarter at 307 Exchange Alley. The food is great, and they too have excellent
vegan desserts. Here's a link to an article about it:
http://www.loveneworleans.com/tastes/olddogfull.html .
I found two other vegetarian restaurants that I never heard of by going to
http://www.bestofneworleans.com/cuis/index.html and selecting vegetarian in the
search box near the end of the page. I can't vouch for how good these are or
whether they're still there.
I recently saw a more comprehensive list of restaurants that offer veg. dishes,
but now I can't find it. I'll send it on to you if I do. In the meantime, I hope
this helps!
Susan (former and perhaps future Louisianian)