I used to have this as a treat when I was younger, now I make it for my children.
Grease a swiss roll tin.
Melt the Marg, syrup and 5oz milk cooking chocolate slowly in a large pan.
Add the biscutes and Maltesers and mix together well.
Press the mixture into a swiss roll tin and chill.
Meanwhile melt your 14oz cooking chocolate.
Pour the cooking chocolate over your chilled mixture and spread evenly, shake the tin side to side to help it even out.
Chill again and cut into squares to serve.
It's best to cut this as you need it or the inside of the maltesers start to melt.