Put dates in a bowl and cover with hot water and set aside.
Combine all the ingredients for the crust well, then press it firmly into the base of your slice tin (mine was 23cm X 32cm). Pop it in the fridge while you crack on with the next layer.
Drain the water off the dates then put them in your trusty food processor. Pulse to break them down. Add everything else except the oil and whizz it all together, making a paste. Add the oil and whizz it again. It should look a lot like caramel.
Take the base from the fridge and spread the caramel layer evenly over the crust. Pop it back in the fridge while you make the chocolate.
Mix everything together to make a smooth runny chocolate. You will probably need to sift the cacao so there will be no lumps.
Pour the chocolate over the caramel layer and spread it over evenly.
Pop it back in the fridge and let it set for at least 3 hours before cutting into squares.
It needs to be kept in the fridge as the chocolate will melt at room temperature.