So we bought some sugar-free ginger biscuits at a food fair and- to be honest - they were awful! We thought about pouring custard over them but that seemed a bit feeble so here's what happened:
Bash the biscuits into crumbs. (Stick them in a plastic bag and hit them with a rolling pin). Melt about an ounce of butter. Yes, it has to be butter. Low-fat spreads don't hold their shape. This is the only naughty bit in the whole process! Add the crumbs and stir around until they are well covered, then press them into the bottom of a serving dish.
Give the cheese mixture a really good stir then pour it onto the biscuit base. Put it back in the fridge to set, preferably overnight. Make a nice pattern on it if you like or you can just spread it thusly: