If there's a thing great bakers know, it's that butter is God. Au Kouing-Amann has great bakers.
I'd like to recommend this place for it's eponymous dish, but it might mean more people will go and then there won't be any more for me. Sure, I'll slim down a bit, but who cares? My girlfriend? Who's she? My doctor? He'll get over it!
So my recommendation is: don't go! Stay in your house with your skinny figure and butterless misery. Never discover the wonderful world of butter, sugar and flour in their perfectly decadent balance.