Oh My, this stuff is good even if it has about a squillion calories. Both my gran and my mom used to make this when I was a kid, my gran's caramel was always a bit more on the runny side and my mom's more on the chewy side, both were great! The recipe my mom uses calls for golden syrup to use in the caramel, which I can't get here but the other day I had a brainwave, why not use dulce de leche?
So, the base is just shortbread, I used a generic type of recipe from an ancient cookbook, you could just use your favourite shortbread recipe. Then I poured about 3/4 of a tin of dulche de leche* over the cooked shortbread and popped it in the fridge to cool completely then melted some chocolate and poured that over the top. Put it back in the fridge to set. Be warned, it is REALLY sweet! Perfect with a nice cup of afternoon tea.
*To make the dulce de leche, read this post, this time I wanted the caramel to be a bit runnier so I boiled the tin for an hour. I actually do more than one tin at a time and stick the unopened tin in the pantry for another day.