Madeleines were Proust’s favorites. I must say I love them too, and they are not the easiest to bake.
I found a french brand that sells good madeleines, quite close to the original version, and they are very practical to carry in your handbag or to give to children, as they have individual packaging. They are a bit expensive and quite rich, so I only buy them as occasional treats.
You can find ingredients and possible allergens here.