I'm not sure if this is the same as fondant icing but I have a packet of "Fix & Fertig Zuckerguss" from
Schwartau for icing cookies etc. Just open the packet and smooth over. The packet I have is too small for a whole cake and not sure if you can get bigger packets. I also have coloured zuckerguss pens for creating pretty patterns on cookies. If this is not exactly what you are looking for, I'd still look at what else
Schwartau have to offer, as they have a few easy baking products.
edit: we bought these products from REWE, I believe.