Millionaire tart is a luxurious switch up of the classic Scottish shortbread made into a tart that is filled with gooey caramel and topped with a luscious chocolate ganache.
Shortbread was developed in the 16th century and has been attributed to Mary, Queen of Scots, who was said to be especially fond of the buttery confection that was originally flavoured with caraway seeds. Over the centuries, it has evolved and various toppings such as candied orange peel, almonds, and chocolate were added.
Also called caramel shortbread, caramel squares, caramel slice, chocolate caramel shortbread and Wellington squares, it eventually earned its name probably because it has become an extremely rich version of the classic shortbread.
It is befitting that there’s a saying, “The millionaire’s shortbread is often richer in calories than the one who tastes is in hard cash” because this is a dessert that you don’t want to overindulge in.
I opted for a true shortbread for the biscuit base so there’s no egg, leaven or additional flavouring as in most other millionaire shortbread recipes online. I’ve also found that using a food processor creates a dough that has just the right amount of kneading for a tender but not crumbly crust, but you can also knead it by hand.
Even though I’m making a tart, I pressed the dough directly into the tart pan so that I don’t handle the dough too much by rolling it out. Then using a glass tumbler, I rolled it to an even thickness with a rim all around. Then chill it before baking so that it holds its shape and does not melt in the hot oven.
If you’ve failed in caramel-making as I often did, this method has been the best I’ve ever experienced. I find that using white sugar is so much easier than brown sugar because I can see when a colour change occurs in the caramel. Turn off the heat when it reaches the desired colour and the rest of the ingredients are incorporated in the residual heat. Be sure to let it cool before pouring over the base, and cool further in a chiller until almost firm.
Chocolate ganache can be made either by heating the cream first and pouring into the chocolate, or melting the chocolate and then adding the cream. Either way, it should be stirred until it forms a smooth consistency to be poured over the firm caramel.
I like to sprinkle salt and lemon zest over the ganache, but you may use any topping such as candied orange peel, candied ginger, almond flakes, pistachios or white chocolate to distinguish your confection.
It is important to note that you must chill the tart after each layer so that you can see the distinct layers when cutting into the tart.
- Shortbread crust:
- 180g all-purpose flour
- 120g unsalted butter
- 60g castor sugar
- ¼ tsp salt
- 225g granulated sugar
- ¼ tsp salt
- 60ml cold water
- 80ml heavy cream
- 60g unsalted butter
- 225g semi-sweet chocolate
- 60ml heavy cream
- Maldon sea salt
- Lemon zest
- Pulse crust ingredients in a food processor until they form a dough. Stop pulsing the moment they come together to avoid overworking the dough.
- Press the dough into a tart pan with a glass tumbler to form an even half-centimetre thick base with a raised rim. Prick the dough all over the bottom and sides with a fork. Chill in the refrigerator for about 15 minutes to rest the dough.
- When rested, bake in a preheated oven at 180°C for about 12 to 15 minutes or until golden colour, not brown. Cool completely before filling with caramel and ganache.
- To prepare caramel, spread sugar into a heavy bottom pan, then slowly add water to soak the sugar.
- Heat the pan to medium and simmer until the water boils away. When the sugar starts to colour, turn the heat down to low and swirl the pan to keep the sugar moving for an even browning.
- Remove from the heat when the caramel reaches a deep golden to copper colour. Carefully pour in the cream and salt and stir until it thickens as it cools.
- Continue stirring until it is warm to the touch, then stir in butter to combine into a gooey sauce.
- Pour the caramel into the crust and spread out evenly to about a half-centimetre thickness and allow the layer to set in the refrigerator for about 30 minutes.
- To prepare ganache, place chocolate into a heatproof bowl. Heat cream in a saucepan and bring to a light simmer. Pour hot cream over the chocolate and whisk until smooth and glossy.
- Pour ganache over caramel and spread to an even layer. Create ripples on the top surface with a pastry knife, then sprinkle Maldon sea salt and grate lemon zest over the top.
- Refrigerate until ganache sets for at least 30 minutes to 1 hour before serving.