This easy, homemade chocolate caramel slice aka Millionaire's shortbread is built on a foundation of whipped shortbread, filled with sweet and salty caramel, topped with a layer of dark chocolate.
What is a Chocolate Salted Caramel Slice?
Here in New Zealand, every single supermarket, convenience store and bakery worth its weight in gold will be selling Caramel Slices (alongside the lolly cake slice, ginger slices, and brownies).
What New Zealand and Australia call caramel slices, the rest of the world may know as millionaire's shortbread. This sweet treat begins with a shortcrust biscuit base which is then generously slathered with caramel and then topped off with dark or milk chocolate.
The first known recipes for this delightful little confectionery date back to the 1970s in Australia. With "millionaire's shortbread" seeming to have originated in Scotland.
I have had my fair share of caramel slices here in New Zealand. My favourite is that made with salted caramel. I love salt (I am the Salty Ginger), and I love it when it's combined with a sweet treat.
For a South African twist, why not have a look at my peppermint crisp caramel slice!
What you need for this recipe
Whipped Shortcrust Biscuit Base
Butter is a key flavour in these biscuits. If using salted butter, simply leave out the additional salt, if using unsalted butter, additional salt is a must!
Flour - plain, standard grade or all-purpose flour is what this recipe calls for.
Icing Sugar or Powdered Sugar adds sweetness with the added starches giving the biscuit a tender snap.
Caster sugar can be substituted with white granulated sugar. Plain white or caster sugar gives a crispness to this biscuit that is otherwise completely lost with just using icing sugar.
Salt - add if using unsalted butter. The salt brings out the flavour of the butter and flour.
Notes - in my testing phase, I did try the ever-popular biscuit bases made with melted butter. I didn't like it, the base seemed oily and I knew I could make a better shortcrust.
This particular caramel slice is made without coconut, but you can include 100 grams of desiccated coconut should you wish.
Brown sugar - this is a caramel filling after all and needs sugar to form a delightful caramel in the end.
Full cream condensed milk adds sweetness and creaminess. Do not use a low-fat version as the fat in the condensed milk is necessary for the caramel to thicken and set up.
Golden Syrup adds flavour and keeps the caramel soft, even though it sets enough to be sliced.
Butter is a crucial element in caramel. It adds fat and richness.
Salt - to give the caramel its salty deliciousness. Here you need to measure according to taste. I found that 2 teaspoons of sea salt give a nice saltiness.
Notes - in my testing phase, I tried some very popular caramel fillings that did not contain golden syrup and way less butter. This resulted in a very thin lacklustre caramel filling, in my opinion.
Dark chocolate and a neutral oil such as coconut oil or even some butter. This allows the chocolate to be sliced without cracking. I suggest using 50% dark chocolate, I tried 72% and it was just too much for me. This is a personal choice.
Making the Slice
Whipped Shortcrust Base
Making the biscuits begins with room temperature butter that is soft enough to beat and whip. The butter and sugars are then whipped together until light and fluffy.
The flour is then added to the butter and mixed in using a spatula or wooden spoon until all the flour is coated. The biscuit dough is then kneaded together 3 to 5 times until it turns into a nice cohesive ball.
Place the biscuit dough into the prepared tin and press down at evenly as possible. Using a fork, poke the biscuit base before baking for 15- 20 minutes.
TOP TIP - if the dough of your shortbread feels too crumbly, work it a bit more with the spatula.
Place the butter, syrup, condensed milk in a medium-sized saucepan and bring to a boil, stirring the entire time all the ingredients are melting together. Once the caramel has started to heat up and boil, whisk/stir constantly for 5 to 10 minutes until the caramel has started to thicken and brown.
To test the caramel, take a cold teaspoon or knife and dip it in, if it sets up fairly quickly the caramel is done.
Take off the heat and stir through the salt and vanilla.
Pour the caramel filling over the biscuit base and bake at 180°C for 10-15 minutes. Once the edges have just started to caramelize, remove from the heat and allow to cool completely.
In a heatproof bowl, place the chocolate and butter or oil, and zap in 20-30 second increments until the chocolate is melted, stirring after each interval. Alternatively, melt the chocolate in a glass dish over a pot of water on the stove. Do not let the water touch the bottom of the glass bowl. Do not get water into the chocolate, the chocolate will seize.
Pour the chocolate over the cooled caramel filling, and spread evenly using the back of a spoon or offset spatula. Allow the slice to cool completely before slicing. You can place the entire tin into the fridge for at least 2 hours or overnight.
Pro Tips for this Recipe
When lining the slice tin, make sure you have an overhang on each side of the tin, this allows for easy removal.
Stir the caramel constantly to ensure the caramel doesn't catch at the bottom of the saucepan.
The caramel layer needs to be cool but not necessarily cold before adding the chocolate, this keeps the slice layers crisp and neat.
Weighing ingredients is more accurate than using measuring cups overall, and this is my recommendation for my recipes as they are all developed and tested using grams only. However, I have activated the US customary conversions on the recipe card, these are based on generally accepted conversions. Cups are equal to 236mL/ 8 fluid ounces, tablespoons are 15mL and teaspoons are 5mL.
Measuring cups and spoons are an essential addition to every kitchen! Especially if you don't use a kitchen scale. For accurate measuring invest in a set to make sure you are adding the correct amount of ingredients. When in doubt - always use a level spoon or cup measure.
Fan-forced or fan assisted oven temperature must be decreased by 20°C/25F. Use an oven thermometer to determine the accuracy of your oven dial.
Pin for Later!
Caramel Slice / Millionaire's Shortbread FAQ
Yes. Wrap the slice in plastic wrap and foil in individual servings. Allow the slices to thaw before serving.
The trick is to add a neutral oil to the chocolate. To get clean even slices, mark your slice using a ruler, and then warm up your sharp knife in hot water, wipe dry and cut. By warming up the blade and wiping it clean in between each slice you will get perfect slices.
The caramel slice should only be cut once the caramel and chocolate have set completely. To ensure this, place the slice in the fridge for two hours or overnight.
The caramel was not cooked enough. The easiest way to prevent this is to test the caramel by using a cold teaspoon or knife. If the caramel sets up fairly quickly and doesn't run, your caramel is ready to pour over the biscuit base. If the caramel is still fairly runny, cook it longer. Baking the caramel for 15 minutes until the edges are bubbly and dark will also ensure the caramel sets properly.
Nothing really. They both have a shortcrust biscuit base, a caramel filling and are topped with chocolate. Many Australian and New Zealand varieties also contain coconut in the biscuit base.
Caramel slices can be stored in an airtight container at room temperature for about 5 days. When frozen, for up to 3 months.
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Chocolate Caramel Slice (Millionaire's Shortbread)
Whipped Shortbread Base
- 180 grams butter
- 50 grams icing sugar
- 100 grams caster sugar
- 250 grams plain or standard grade or all-purpose flour
- ½ teaspoon salt if using unsalted butter
Salted Caramel Filling
- 100 grams brown sugar
- 397 grams 1 tin full cream condensed milk
- 50 grams golden syrup or light corn syrup
- 125 grams butter
- 2 teaspoon sea salt salt to taste
- ½ teaspoon vanilla extract
- 180 grams dark chocolate
- 30 grams butter or coconut oil
Whipped Shortbread Base
- Preheat the oven to 200°C/390F/Gas Mark 6. Grease and line a 20-23 cm square cake tin with parchment paper leaving an overhang to allow for easy removal of the slice.
- Soften the butter to a whipping consistency. If room temperature butter is not soft enough, pop in the microwave for 15-second bursts until soft but not melted. Beat the butter, caster sugar, icing sugar together using a stand mixer, electric handheld mixer or whisk until the butter is light, fluffy and aerated.180 grams butter, 50 grams icing sugar, 100 grams caster sugar
- Add in the flour and salt, mixing with a spatula or wooden spoon until a soft pliable dough forms. Press this dough into the bottom of the prepared tin. Use the back of a cup measurer or offset spatula to really press the dough into the pan. Prick the dough with a fork throughout and bake for 15 minutes until the biscuit base is a nice light golden brown.250 grams plain or standard grade or all-purpose flour, ½ teaspoon salt
- Allow the biscuit base to cool in the tin while you make the caramel filling.
- Place the butter, syrup, condensed milk in a medium-sized saucepan and bring to a boil, stirring the entire time all the ingredients are melting together. Once the caramel has started to heat up and boil, whisk/stir constantly for 5 to 10 minutes until the caramel has started to thicken and brown. To test the caramel, take a cold teaspoon or knife and dip it in, if it sets up fairly quickly the caramel is done. Take off the heat and stir through the salt and vanilla.397 grams 1 tin full cream condensed milk, 125 grams butter, ½ teaspoon vanilla extract, 2 teaspoon sea salt
- Pour the caramel filling over the biscuit base and bake at 180°C for 10-15 minutes. Once the edges have just started to caramelize, remove from the heat and allow to cool completely.
- In a heatproof bowl, place the chocolate and butter or oil, and zap in 20-30 second increments until the chocolate is melted, stirring after each interval. Alternatively, melt the chocolate in a glass dish over a pot of water on the stove. Do not let the water touch the bottom of the glass bowl. Do not get water into the chocolate, the chocolate will seize.180 grams dark chocolate, 30 grams butter or coconut oil
- Pour the chocolate over the cooled caramel filling, and spread evenly using the back of a spoon or offset spatula. Allow the slice to cool completely before slicing. You can place the entire tin into the fridge for at least 2 hours or overnight.
Nutrition information is an estimate. If scaling the recipe remember to scale your cook and bakeware accordingly.