Michelle Darmody: How to bake Millionaire's Shortbread Squares — and the mistakes to avoid

Millionaire's Shortbread is a layered Scottish dessert made with a shortbread crust, sweet caramel, and topped with a layer of chocolate.

I can only guess that the name for these squares comes from their decadence and richness. 

Three contrasting layers are brought together to create the enduring favourite, one soft, one crisp, and one crumbly.

The soft caramel layer can be the trickiest part to get right. 

A sugar thermometer helps to get the exact temperature, and this will also help you to get consistent results. 

You can buy a sugar thermometer from baking websites or in specialist shops. 

There is another way to test that your caramel is cooking correctly, and this soft ball method described below. 

It is an older way that has been used by confectionary makers for centuries. It is also helpful when making fudge. 

After you drop the spoon of caramel into the water as instructed it should become pliable and soft and be easily moulded between your fingers.

If you have any leftover condensed milk, it is delicious in coffee. A strong espresso poured over some condensed milk is a real treat.

Millionaire's Shortbread

recipe by:Michelle Darmody

Three contrasting layers are brought together to create the enduring favourite, one soft, one crisp, and one crumbly.

Servings

12

Preparation Time

 40 mins

Cooking Time

 25 mins

Total Time

 1 hours 5 mins

Course

 Baking

Ingredients

• 240g plain flour

• 75g golden caster sugar

• 175g cold butter, cubed

• For the caramel:

• 80g butter

• 80g light muscovado sugar

• 320g condensed milk

• For the chocolate:

• 195g dark chocolate chips

• 5g butter

Method

1. Line two 8-inch square baking tins with parchment.

2. Mix the flour and sugar and rub in the butter until combined and it looks like rough breadcrumbs. Knead until a smooth dough forms. Press the dough into the tin evening it throughout. Place it into the fridge for at least a half an hour.

3. Preheat your oven to 180ºC/gas mark 4 and bake the base for 25 minutes until a very light golden colour. Allow it to cool completely in the tin.

4. Place all the ingredients for the caramel filling into a heavy based saucepan and place it over a low heat until the sugar has melted. Bring to the boil using a sugar thermometer to ensure it gets between 113ºC and 116ºC. Then lower the heat back down and stir continuously at a simmer for about ten minutes until it begins to thicken.

5. Pour the caramel over the shortbread using a spatula to get it all out of the saucepan. Spread it out and set it aside to cool. If your kitchen is warm, you can transfer it to the fridge to help firm it up.

6. Melt the chocolate and butter in a bowl over a simmering saucepan of water. Scoop it over the cooled caramel, spread it and allow to firm up. Cut into squares with a hot knife.

Baker's tips

• If you are stuck for time, you can make the base of the in a similar way to a cheesecake base by crushing shortbread biscuits. Crush 250g of biscuits and stir in 100g of melted butter until the biscuit crumbs are coated. Press this down into the tin and bake for ten minutes before following the rest of the recipe.
• It is important to boil the caramel for long enough so that is gets to the soft ball stage. It is the trickiest part of this recipe and the most likely to go wrong. If your caramel does not set it will squish out when the slices are being cut and it will also stick to the baking parchment at each side. The caramel mixture needs to reach 113ºC on a sugar thermometer but if you do not have one of these to hand you can test your caramel using the soft ball method. Have a bowl of very cold water ready by your saucepan. Carefully drop some caramel into the bowl of water with a spoon. It should form a small ball in the water that you can press between your fingers.
• If you are using a bar of chocolate rather than chips it is best to break it as evenly as you can, so you do not have very large pieces that take a long time to melt while other little shards are getting burnt.
• Heat a knife in boiling water and use this to cut the slices. If the chocolate top is cracking, it’s a result of too much pressure being applied with the knife rather than the heat doing the work of melting through the chocolate layer.
• The Millionaire Shortbread Squares will last in an airtight container in a cool place for about a week. If your kitchen is very warm you can store them in the fridge, this may, however, discolour the chocolate layer slightly.
• The caramel does not take too kindly to being frozen and defrosted, you will probably end up with a sticky mess, so it is best not to freeze these squares.

3 delicious variations

Salted caramel squares

Add a few pinches of salt to the caramel towards the end of stirring and also sprinkle some flaky sea salt over the chocolate layer before it hardens.

Orange Zest Squares

Adding the zest of two large oranges to the caramel towards the end of stirring it changes the taste of the squares quite considerably. I also sprinkle some zest over the chocolate before it hardens.

Espresso Millionaire Shortbread

To make an espresso version of these squares you can use something called espresso powder. This can be also found on baking websites and in specialist baking shops. It has a more intense flavour than instant coffee and adds a richness to the caramel layer. Two tablespoons of the powder can be added to the caramel. You can add them when you are placing all of the ingredients into the saucepan at the beginning. The caramel is then made in the same way.