Here it is!

1 packet Marie or Milk Arrowroot biccies (anything like that - e.g. Milk Coffee)
1 tin condensed milk
100g brown sugar
50g butter
1 bag of dark or milk choc melts

Gently heat the condensed milk, sugar and butter in a medium-sized saucepan - you must constantly stir it and ensure that you don't overheat it, or it will start to burn and get clumpy (although some clumpiness doesn't affect the flavour LOL - I'm guilty of frequently doing it and nobody knows ROFL).

Cook the mixture until it thickens and bubbles and has changed to a dark caramel colour (oooh the smell is divine, as is licking the bowl when you're done!).

Break up the biscuits into smallish pieces and add to your caramel and mix well. Pour into a lined brownie tin (it can get a bit sticky so I use non-stick baking paper) and spread it out (it will be lumpy!).

Melt your chocolate and pour over the caramel and put in the fridge. You'll need it in the fridge for a bit to allow the caramel to set as well as the chocolate, and then you can cut it into squares.

Easy peasy!