Thank you for replying, I will let you know how my next batch goes. CheersI would be tempted to try adding 250-500g of Maltodextrin.
It's a little out of vogue but was once a widely used (often overused - hence it's being out of favour).
Maltodextrin (what the Americans call "Corn Syrup") is a manufactured homolog of some of the unfermentable products you get from the action of enzymes on malt in mashing, especially if you mashed hot for a high body beer.
By saying you would think of adding Malt, I presume you mean Malt Extract (malt is grain, ME is the liquid or dry powder extracted from it). Malt extract is largely fermentable, the part that isn't would be very similar to what you get from Maltodextrin, it would also bring a lot of flavours with it.
There in lies the rub. Malt Extract or Hops would change the taste a fair amount. Especially hops, I love hops, love pepper in cooking to, but don't often put it in desserts. Its very possible for one good flavour to be incompatible with another good flavour.
Mind you there is a fine old tradition of people making Graf - have a read if that sort of thing interests you.