I am considering doing this to perfect the finish on my fondant cakes, I have done in the past with great results, but not sure if I should do this as standard? Just wondering how many of you do this? I notice that many of the well established cake makers here in the UK state in their books that they recommend doing this as standard (eg Maisie Fantasie, LVCC) and am just wondering what the general thought is and if any other do this?

If you do do you do a really thin layer first then a thicker layer to finish, or two regular thickness layers?

I'm in the US, but I have a lot of UK cake books. Most of them show double-layering with marzipan and paste/fondant. I personally love marzipan but it is expensive. Just keep in mind that you have to pass that expense on to your customers.

Yeah you are right Annie - its going to be costly....I will have a think about this, before I adopt as standard practice.

I don't see the point for normal sponge cakes, it's just an extra expense and a lot of people don't like huge thick pieces of fondant on cakes. For fruit cakes, definitely do a double (usually marzipan/fondant), but for sponges I use ganache instead of buttercream then 1 thin layer of fondant.

From a customers point of view, I dont really like marzipan under fondant on sponge cakes eating it I find it too heavy for the taste/texture of the cake. Similarly I cant imagine two regular thickness layers of fondant would be pleasant to eat, especially with sponge cake.
Marzipan under fondant/RI on fruit cakes I would expect (and really like the taste).

Almost all books by UK cake artitsts recommend the double-layer method. I have pondered this for about 3 minutes but I would never sacrify taste for looks and 0,5 cm marzipan plus 0,5 cm fondant is almost half an inch of sugar... yuck.

So I rather live with a not oh-so-perfectly-smooth cake (which my clients never notice anyway) and rest assured that the cake is eaten and enjoyed, because that is their primary raison d'être