Preheat the oven to 180 C (160 C fan).I use a 22cm square (8") non stick tin with a loose bottom and I have cut out a square of bake o glide which I stick in the bottom.
I use a food processor or free standing mixer to rub 125 grams butter, 100 grams of sugar and 200 grams of flour into rubble. But you can use a mixing bowl and mix the butter, sugar and flour together with a wooden spoon to get the same result. Add the sugar and mix together until it starts to come together.
Tip the sandy mixture into the tin and using your fingers/knuckles gently spread out and press the mixture into a level layer. It will appear at first that it is not enough mixture but persevere and you too will see the light.
Bake until golden brown-about 12-15 mins. It is important that it does have a golden tinge on the surface. let it cool completely.
To make the caramel, empty all the ingredients into a saucepan and bring to a fast boil. Stir regularly to prevent the caramel burning on the bottom of the pan. When the caramel reaches 120 C (I sometimes use a sugar thermometer )or just past the soft ball phase it is ready. To tell when it reaches this stage without a thermometer I put a cup of really cold water next to me and using a teaspoon carefully drop a small amount of the caramel into it when I think it might be ready. When it forms a ball in the water take it off the heat.
Pour the caramel onto the shortbread and allow to cool completely. Be super careful, that bad boy is hot.
Melt 200 grams of milk chocolate carefully in a bowl placed over simmering water. Milk chocolate is difficult to melt in the microwave so I don't even go there. Pour satisfyingly over the caramel and chill for a couple of hours before cutting into 5 cm squares with a sharp knife.
OMG Apply to Child's Face only. Strictly no old women called Jenny.