In this article
My friend Margaret grew up in England, and whenever she goes home she checks the cafe cabinet before she looks at the menu. If the millionaire’s shortbread is good, she says, everything else will be good too. It is Scotland’s caramel shortbread, three layers in one small square: a crisp, sandy butter shortbread on the bottom, a thick band of soft caramel in the middle and a thin layer of chocolate on top that snaps when you bite it. In America we would call them caramel bars. In Britain they are in every tea room, every bakery and every lunchbox, and the story goes that they got their name because they are so rich only a millionaire could afford to eat one every day.
Margaret’s rule is the caramel. It is made from butter, brown sugar, golden syrup and sweetened condensed milk, and it has to be cooked and stirred the whole time over gentle heat until it darkens to the color of fudge and thickens enough to hold a line when you drag a spoon across the bottom of the pan. That takes 8 to 10 minutes once it starts to bubble. Pull it too soon and the caramel stays pale and runs out the sides when you cut the squares. Stop stirring and it catches and burns on the bottom of the pan. Get it right and the middle layer is soft and chewy, sets firm enough to slice clean, and bends rather than oozes.
Why this millionaire’s shortbread works
- A shortbread baked pale. The base is baked only until it is light golden, so it stays crisp and sandy under the caramel instead of hard.
- Condensed milk caramel. Sweetened condensed milk cooked with butter and sugar thickens into a soft, chewy caramel that sets without a candy thermometer.
- Constant stirring. Condensed milk scorches easily. Stirring the whole time, scraping the bottom, is what keeps the caramel smooth.
- Cooked until it holds a line. The color and the line on the bottom of the pan tell you the caramel is thick enough to set and slice.
- Cold caramel before the chocolate. Chocolate poured over warm caramel slides and streaks. Chilled caramel gives a clean, flat top.
Ingredients
Makes one 9 inch square pan, 16 squares. The measurements are in US cups with grams in brackets, the grams being the British weights Margaret uses.
For the shortbread base
- 1 1/2 cups all-purpose flour (190g)
- 1/3 cup granulated sugar (65g)
- 1/4 teaspoon fine salt
- 3/4 cup cold unsalted butter, cubed (170g)
For the caramel
- 1/2 cup unsalted butter (113g)
- 1/2 cup packed light brown sugar (100g)
- 2 tablespoons golden syrup or light corn syrup (40g)
- 1 can sweetened condensed milk (14 ounces, 397g)
- 1/4 teaspoon fine salt
For the top
- 7 ounces milk chocolate, chopped (200g)
- 1 ounce dark chocolate, chopped (30g), optional, for drizzling
Margaret uses golden syrup, a thick pale British cane syrup sold in most large American supermarkets. Light corn syrup works in its place. Use sweetened condensed milk, not evaporated milk: they are not interchangeable here.
How to make millionaire’s shortbread
- Heat the oven to 350 degrees (175°C). Line a 9 inch square pan with parchment, leaving the paper hanging over two sides so you can lift the bars out later.
- For the base, mix the flour, sugar and salt in a bowl. Rub in the cold butter with your fingertips until the mixture looks like damp sand and holds together when squeezed. Press it firmly and evenly into the pan and prick it all over with a fork.
- Bake for 20 to 25 minutes, until pale golden at the edges and just firm in the middle. Let it cool in the pan while you make the caramel.
- For the caramel, put the butter, brown sugar, golden syrup, condensed milk and salt in a heavy saucepan over medium low heat. Stir until the butter melts and the sugar dissolves.
- Bring it to a gentle bubble, then keep stirring constantly, scraping the bottom and corners of the pan, for 8 to 10 minutes, until the caramel turns a deep fudge color and is thick enough that a spoon dragged across the bottom leaves a line for a second or two.
- Pour the hot caramel over the shortbread and spread it evenly. Let it cool, then chill for 30 minutes, until firm.
- Melt the milk chocolate in a bowl over a pan of barely simmering water, or in short bursts in the microwave, stirring often. Pour it over the cold caramel and tilt the pan to spread it. Drizzle the melted dark chocolate over the top if using, and drag a toothpick through it for a feathered look.
- Leave at room temperature for about 1 hour, until the chocolate is set. Lift out by the paper and cut into 16 squares with a large knife dipped in hot water and wiped dry between cuts.
Tips that make the difference
- If the caramel starts to darken in spots or smell scorched, turn the heat down at once and keep stirring. A heavy saucepan helps a great deal.
- Do not chill the finished bars before cutting them. Cold chocolate cracks under the knife; set at room temperature, it cuts clean.
- For the neatest squares, trim a thin strip from each edge first. The trimmings are the baker’s share.
- A pinch of flaky salt over the chocolate before it sets turns them into salted caramel squares.
Variations
- Dark chocolate top. Use all dark chocolate for a less sweet bar that grown men in my family prefer.
- Shortbread with oats. Swap a quarter of the flour for quick oats for a crunchier, more rustic base.
- Pecan. Scatter chopped toasted pecans over the caramel before the chocolate goes on, an American touch Margaret allows.
- Bigger batch. Double everything and bake in a 9 by 13 inch pan; the base needs about 5 minutes longer.
Storage and make-ahead
Keep the squares in an airtight tin at cool room temperature for up to 1 week, with parchment between the layers.
In a warm kitchen, store them in the refrigerator and let them stand for 15 minutes before eating so the caramel softens.
They freeze well for up to 3 months. Wrap them in plastic and thaw in the refrigerator.
Frequently asked questions
Why is it called millionaire’s shortbread?
The story goes that the name comes from how rich it is: shortbread, caramel and chocolate all in one square, more than an ordinary person would treat themselves to every day.
Why did my caramel not set?
It was not cooked long enough. The caramel needs 8 to 10 minutes of constant stirring once it bubbles, until it turns fudge colored and a spoon dragged across the pan leaves a line.
Why did my chocolate crack when I cut it?
The bars were too cold, or the knife was dry. Let them sit at room temperature and use a knife dipped in hot water and wiped dry.
Is it the same as American caramel bars?
Very close. Millionaire’s shortbread always has a true shortbread base, rubbed by hand and baked pale, and a thick condensed milk caramel.
Bake the shortbread pale, stir the caramel the whole time, and wait for the chocolate to set. Margaret says that is all the British secret there is.
Millionaire's Shortbread (Scottish Caramel Shortbread Bars)
Margaret's millionaire's shortbread, the Scottish caramel bar in every British cafe: a butter shortbread base, a thick condensed milk caramel cooked for 8 to 10 minutes until fudge colored, and a snap of milk chocolate on top. 9 inch square pan, US cups with grams.
Ingredients
- 1 1/2 cups all-purpose flour
- 1/3 cup granulated sugar
- 1/4 teaspoon fine salt
- 3/4 cup cold unsalted butter, cubed
- 1/2 cup unsalted butter
- 1/2 cup packed light brown sugar
- 2 tablespoons golden syrup or light corn syrup
- 1 can sweetened condensed milk
- 1/4 teaspoon fine salt
- 7 ounces milk chocolate, chopped
- 1 ounce dark chocolate, chopped (30g), optional, for drizzling
Instructions
- Heat the oven to 350 degrees (175°C). Line a 9 inch square pan with parchment, leaving the paper hanging over two sides so you can lift the bars out later.
- For the base, mix the flour, sugar and salt in a bowl. Rub in the cold butter with your fingertips until the mixture looks like damp sand and holds together when squeezed. Press it firmly and evenly into the pan and prick it all over with a fork.
- Bake for 20 to 25 minutes, until pale golden at the edges and just firm in the middle. Let it cool in the pan while you make the caramel.
- For the caramel, put the butter, brown sugar, golden syrup, condensed milk and salt in a heavy saucepan over medium low heat. Stir until the butter melts and the sugar dissolves.
- Bring it to a gentle bubble, then keep stirring constantly, scraping the bottom and corners of the pan, for 8 to 10 minutes, until the caramel turns a deep fudge color and is thick enough that a spoon dragged across the bottom leaves a line for a second or two.
- Pour the hot caramel over the shortbread and spread it evenly. Let it cool, then chill for 30 minutes, until firm.
- Melt the milk chocolate in a bowl over a pan of barely simmering water, or in short bursts in the microwave, stirring often. Pour it over the cold caramel and tilt the pan to spread it. Drizzle the melted dark chocolate over the top if using, and drag a toothpick through it for a feathered look.
- Leave at room temperature for about 1 hour, until the chocolate is set. Lift out by the paper and cut into 16 squares with a large knife dipped in hot water and wiped dry between cuts.
