Millionaire’s shortbread is such a classic slice of joy - crumbly shortbread base, sweet amber caramel filling and a thin chocolate top. They’re the perfect mid-afternoon pick-me-up dose of sugar to go with a cup of coffee or tea. Or just eat them all day long like I do!
✏️ Making a tasty and easy recipe
I tried a few different variations of this recipe but eventually found that delicious combination. I love including cornflour (cornstarch in the US) in the shortbread base to give it a shorter texture.
Also, using sweetened condensed milk to cook up your own caramel allows you to give it the perfect amber colour while still keeping it simple.
🥘 Ingredients notes
- I prefer to use vanilla extract rather than vanilla essence, as it has a better stronger flavour. It’s a purer vanilla taste as it’s less processed than vanilla essence.
- Always sieve your flour. I used to be a bit lazy and skip this part, but it really makes such a difference to get you a lump-free mixture.
- When measuring your ingredients, I always recommend using weights rather than cups for greater accuracy.
🔪 Equipment notes
- I like to use digital scales for weighing my ingredients as it's easier and more accurate than other scales (or using no scales!). I'm a fan of these KitchenAid or Salter ones!
- Use measuring spoons for your teaspoon and tablespoon amounts where possible. Make sure the scoops filled with your ingredients are levelled before adding them to your mix!
Store your shortbread bars in an airtight container at room temperature. It should stay fresh for up to 4 days.
If it's hot where you live, you might prefer to store these bars in the fridge instead. They should last up to 5 days in the fridge.
If keeping in the fridge, you may want to bring your millionaire's shortbread slices up to room temperature before eating. They might be too hard for your teeth otherwise!
💭 Top tips for success
The first time I made these, my chocolate layer came out with white streaks! This was because I’d been a bit lazy... I'd melted my chocolate too quickly in the microwave. I'd also used a fairly cheap brand of cooking chocolate (which I will steer clear from in the future!).
I recommend heating the chocolate nice and slowly over a bain-marie (a heatproof bowl over a pan of hot water). Heat only two-thirds of the chocolate in the bain-marie. Once this has mostly melted, take it off the heat and add the remaining third and stir until smooth. This probably won’t actually temper your chocolate (you’d need a bit more faffing and thermometer to nail that), but should help your chocolate layer to be smooth and streak-free.
Alternatively, get yourself on the couverture chocolate hype! This is essentially a fancier cooking chocolate that melts like a dream and was made for pro chocolate work. You don’t really need to temper it for the millionaire’s shortbread. I'd just melt these gorgeous chocolate buttons slowly and you’re good to go. My favourite brand is Callebaut milk chocolate and Callebaut white chocolate callets.
If you’ve got any specific questions on making these millionaire's shortbread traybake slices, please feel free to leave a comment below and I’ll try my best to help out!
♻️ Alternatives and substitutions
Personally, I like my chocolate layer to have that bit of bite and snap. If instead, you prefer a slightly softer chocolate top, add 1 tablespoon of double cream, vegetable or coconut oil. A softer layer allows you to bite into your millionaire’s shortbread slice without the caramel layer getting squished out of the sides. It’s a lot less messy, but I often snaffle mine so fast I’m not too fussed by the extra mess for that pure bite.
I like to use white chocolate and milk chocolate for my traybake topping, but you can easily use the same quantities of chocolate and use either full milk, white or dark chocolate, or even a combo of them all.
If you like salted caramel, you can add even more salt to the caramel layer. This recipe calls for ¼ teaspoon of salt, but you can increase this to 1teaspoon of salt for a strong flavour.
For a gluten-free version, you can swap the regular plain/all-purpose flour for a gluten-free plain/all-purpose flour blend of the same quantity.
If anything, this can make your shortbread even “shorter”. You'll get a lovely soft crumbly crust for your caramel shortbread bars!
To be safe, always check your other ingredients for allergen warnings on the nutritional label, as they may have cross-contamination warnings.
🧁 Other goodies
I definitely recommend that you whip up a batch of these delicious millionaire's shortbread traybake bars! But as an avid home baker, I’m sure you’re asking yourself “what next?”.
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- 130 g (½ cups) unsalted butter (room temp.)
- 50 g (¼ cups) golden caster sugar
- 165 g (1⅓ cups) plain/all-purpose flour
- 10 g (2 teaspoon) cornstarch (cornflour in the UK)
- ¼ teaspoon salt
- 300 g (1 cup) sweetened condensed milk
- 75 g (⅓ cups) light brown soft sugar
- 75 g (⅓ cups) unsalted butter
- 2 tablespoon golden syrup
- 1 teaspoon vanilla extract
- ¼ teaspoon salt
- 150 g (¾ cups) milk chocolate (or dark)
- 50 g (⅓ cups) white chocolate
- 1½ tablespoon heavy cream or coconut/vegetable oil (optional)
- Pre-heat oven: 180°C / 160°C (fan) / Gas Mark 4 / 350°F
- Cream together the butter and sugar until fully combined.
- Add in the vanilla extract and sift in the flour and mix together until a smooth dough forms.
- Line an 8inch square baking tin with greaseproof paper and press the dough into the base of the tin, making sure to press firmly until you get an even layer. You can use your hands or the back of a large spoon.
- Using a fork, poke little holes across the base to help it cook, then bake in the oven for 20mins until lightly golden.
- In a small saucepan, heat the condensed milk, sugar, butter and syrup over a medium heat. Whisk continuously, bringing it to the boil. It will bubble and simmer as you stir.
- Once the mixture darkens to a nice amber caramel and thickens, roughly 15-20mins, take it off the heat.
- Add the vanilla extract and salt, stirring through before allowing the caramel to cool for a few minutes in the pan. Pour the caramel over the cooked shortbread and allow this to cool for a minimum of 3hrs at room temperature.
- Once the caramel layer has cooled, begin making the chocolate top. Firstly by breaking up or chopping the chocolate (keeping the milk and white separate) into small pieces ready for melting.
- Slowly melt the milk chocolate, either in a double-boiler/ bain-marie or in the microwave (in no more than 30sec bursts). Stir the chocolate to ensure no pieces of solid chocolate remain, and the melted chocolate is nice and smooth. If using, stir in 1 tablespoon of cream/oil.
- In a separate heatproof bowl, melt the white chocolate in the same process as above, stirring to ensure smooth. If using, stir in ½ tablespoon of cream/oil.
- Pour the melted milk chocolate over the cooled caramel, then top with the melted white chocolate drizzling in thin lines. While the chocolate is still hot, swirl through the two chocolates with a skewer or knife to give a nice pattern.
- Allow the chocolate to cool and set in the fridge for 30mins before cutting into slices to serve.
Nutritional information is an estimate based on an online nutritional calculator, actual values may vary.