Whether in small sqaures or bars, this caramel shortbread is always popular. The different textures are the principal appeal - the crunch of the shortbread base, the caramel in the middle and the cold, crisp chocolate on top.

For the shortbread:
250g plain flour
75g caster sugar
175g butter, softened
For the caramel:
100g butter or margarine
100g light muscavado sugar
2 x 397g cans condensed milk
For the topping:
200g plain or milk chocolate, broken into pieces

Pre-heat the oven to 180'C/Gas mark 4. Lightly grease a 13 x 9inch (33x23cm) Swiss roll tin.
To make the shortbread, mix the flour and caster sugar in a bowl. Rub in the butter until the mixture resembles fine breadcrumbs. Knead the mixture together until it forms a dough, then press into the base of the prepared tin. Prick the shortbread lightly with a fork and bake in the pre-heated oven for about 20 minutes or until firm to the touch and very lightly browned. Cool in the tin.
To make the caramel, measure the butter, sugar and condensed milk into a pan and heat gently until the sugar has dissolved. Bring to the boil, stirring all the time, then reduce the heat and simmer very gently, stirring continuously, for about 5 minutes or until the mixture has thickened slightly. Pour over the shortbread and leave to cool.
For the topping, melt the chocolate slowly in a bowl over a pan of hot water. Pour over the cold caramel and leave to set. Cut into squares or bars.