Step 1

Preheat the oven to 150C/300F/Gas Line a 23cm/9in square cake tin with baking parchment.

Step 2

Combine the flour and butter cubes in a food processor and pulse until the mixture resembles fine breadcrumbs. (Alternatively, you can rub the butter in by hand.)

Step 3

Add in the caster sugar and pulse again until combined.

Step 4

Tip the mixture into the lined cake tin and spread it out evenly with the back of a spoon. Then press the shortbread down firmly with your knuckles so that it is tightly packed in the tin.

Step 5

Bake the shortbread for 30 minutes or until very light golden brown. Set aside to cool.

Step 6

Meanwhile, for the topping, heat the butter, condensed milk and golden syrup in a saucepan, stirring occasionally until the butter is melted and the mixture is smooth.

Step 7

Increase the heat and bring the mixture to the boil, stirring frequently. The caramel will thicken and turn golden-brown. Set aside to cool slightly, then pour over the cooled shortbread. Allow to cool completely.

Step 8

Melt the chocolate in a bowl set over a pan of simmering water (ensure that the bottom of the bowl does not touch the water), stirring occasionally.

Step 9

Pour the melted chocolate over the caramel and set aside until the chocolate has cooled completely.

Step 10

Cut into squares and serve.