Note: Normally this is made with caramel (which is why it's also called a Caramel Slice), but I have seen some recipes that call for Dulce de Leche. If you want to use Dulce de Leche just substitute 2 tins of condensed milk for all the caramel ingredients. Instructions for turning them in to Dulce de Leche is below.
Makes 24 squares/pieces
13 x 9 inch pan, greased (butter)
180°C | 350°F | Gas Mark 4
20 minutes (until firm to the touch and lightly browned)
To slice into squares score the chocolate first (6 squares by 4).
Dip a knife in very hot water, then wipe dry and cut the squares.
To avoid the hassle of cutting the chocolate I like to make these in 24 muffin cases so they are already individual portions (it also makes it easy to halve the recipe and make 12).
If you do make individual portions, put the cases in a muffin pan (no need to grease it) when you cook the shortbread to ensure they retain their shape. Also you have to move quickly to share out the caramel because it sets extremely quickly.
To make dulce de leche get two 397g tins of condensed milk and just boil them in water for 4 hours. Be warned! if the cans aren't always fully submerged in water the whole time they can explode!
Remove the paper labels and put the tins on their sides in a large tall pan, then fill with water so there is a good amount of water above the tops of the cans. Put the lid on the pan and bring to the boil and simmer for 4 hours (or at least 3). If the water level starts getting too low boil a kettle full of water and add it to the pan to top it back up. Once they are done leave the whole pan to cool down before removing the tins.