I had this problem too, and some was dripping onto the turbo heatshield too!
I got my gasket set from GSF, exactly the same part as from Audi but only £15, and they had it in stock. The Audi logo had been removed, but the part number was identical.
I've read two guides on replacing the gasket, one said to use sealant and the other said not to...
I didn't use any on mine, and it seems to be fine, no more oil drips or spark plug recesses full of oil, but in hindsight I wish I had used sealant! It's an easy enough job though, so will replace it again if it starts leaking.