The history of millionaire shortbread should start with its base, shortbread, as the indulgent caramel and chocolate version began with the humble shortbread biscuit.
Associated with Scotland thanks to brands such as Walkers, Scottish shortbread originated around the 12th Century, but the biscuit we know and love now is attributed to Mary Queen of Scots in the 16th Century
This is because it was said that she liked Petticoat Tails, a thin, crisp, buttery shortbread originally flavoured with caraway seeds.
The practise of adding toppings or additions to shortbread is thought to date back to the 19th Century, when almonds and candied peel were added for special occasions.
Millionaire or millionaire's shortbread consists of a shortbread based, topped with a thick layer of caramel, topped with chocolate.
It's a three stage process that starts with making shortbread, cooling this then pouring on caramel, letting this cool then spreading on melted chocolate.
While there's no definitive evidence for when millionaire shortbread was created, it is thought that it originated in Scotland.
It is very sweet and rich, which is one of the reasons given for its decadent name.
While the name it accepted to have come from Scotland, a caramel shortbread bar first appeared in Australian Women’s Weekly at the beginning of the 1970s, so say the Guardian.
BBC Good Food have the following recipe.
For the shortbread
For the caramel
For the topping
Heat the oven to 180C/160C fan/gas 4. Lightly grease and line a 20-22cm square or rectangular baking tin with a lip of at least 3cm.
To make the shortbread, mix 250g plain flour and 75g caster sugar in a bowl. Rub in 175g softened 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 for 20 minutes or until firm to the touch and very lightly browned. Leave to cool in the tin.
To make the caramel, place 100g butter or margarine, 100g light muscovado sugar and the can of condensed milk in a pan and heat gently until the sugar has dissolved. Continually stir with a spatula to make sure no sugar sticks to the bottom of the pan. (This can leave brown specks in the caramel but won’t affect the flavour.)
Turn up the heat to medium high, stirring all the time, and bring to the boil, then lower the heat back to low and stirring continuously, for about 5-10 minutes or until the mixture has thickened slightly. Pour over the shortbread and leave to cool.
For the topping, melt 200g plain or milk 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 with a hot knife.
You can also make seasonal millionaire shortbread, such as this Easter treat.