I am the designated haloween biscuit baker. 
I've had a try out today, but spreading the melted chocolate on the biscuits has not worked as well as I hoped. The chocolate is quite thick and lumpy and I have ended up using loads of it too. The dc will no doubt scoff them happily, but they don't look that good.
What is the secret of a smooth thin layer? Do I need one of those little pallet knives with a kink in?