Billionaire's Shortbread

So, after a somewhat unexpected hiatus for work-related purposes, I finally am able to return to the blog. It has been difficult, willing myself into focusing on the Cold war, population change, reversible reactions, Cepheid variables, respiration, poetry and countless other topics, when all I (desperately) wanted was to get back into the kitchen.
Just one more, little exam left. 45 minutes away from freedom- until September. And not a moment to soon. Thankfully it is (for once) not the kind of exam which could be revised for (well, for prolonged periods, anyway), which leaves me time to begin ticking off my endless list of baking goodies.

I have already done a post on Millionaire's shortbread, which I still stand by, but this is something more luxurious. The caramel is more intense and the dark chocolate also adds richness (you could substitute this for milk chocolate, which I would usually be tempted to do, but it works well with dark chocolate). This does take more time and care, but it is definitely worth trying.

Just a little more chocolate...

This can be made over a couple of days; the shortbread can be kept for around 5 days in a tupperware once baked and the caramel can be stored in the fridge.
I couldn't find a 20x30cm tray, so I used a slightly smaller tins. Most of the pieces I did were around 3x5cm rectangles- the rest were little squares.

Recipe from Heston Blumenthal.
He notes that in the Fat Duck, the shortbread is topped with golden nuggets made from fleur de sel dusted with edible gold powder. I couldn't obtain fleur de sel, so just rolled little pieces of rock salt in edible gold dust. This is good for balancing any bitterness of the dark chocolate.

Billionaire’s Shortbread

Makes 20 (or so) bars

Ingredients:

For the shortbread

125g plain flour 

50g ground almonds 

½ tsp baking powder 

½ tsp salt 

110g cold unsalted butter, cubed

100g caster sugar

40g egg yolks (about 2 large egg yolks)

35g olive oil

A little more caster sugar, for dusting

For the salted butter caramel

200g double cream

190g caster sugar

150g unsalted butter

1 tsp salt

185g liquid glucose

190g whole milk

For the chocolate

250g plain chocolate, chopped

10g unsalted butter

     

Method:

1. For the shortbread, sift the flour, ground almonds, baking powder and salt into a bowl and set aside.

2. Cream together the butter and sugar for about 5 minutes, or until pale and fluffy. Add the flour mixture and continue mixing until the appearance is similar to breadcrumbs.

3. In another bowl, beat together the egg yolks and olive oil and gradually add to the breadcrumb mixture until a soft dough is made.

4. Shape the dough, on a very lightly floured surface, into a flat rectangle and wrap in cling film. Refrigerate the dough for at least 2 hours.

5. Unwrap the dough and place between two pieces of baking paper, then roll out into a rectangle measuring around 20x30cm. Cut the dough and baking paper to fit a 20x30cm tray and place in the tray. Place the tray in the freezer for at least 20 minutes. Preheat the oven to 150C/300F/mark 2.

6. Remove the tray from the freezer and discard the top layer of baking paper. Place the tray in the oven for 15-20 minutes, before turning it round to bake for a further 3-5 minutes, or until lightly golden all over.

7. Before allowing the shortbread to cool, slide it from the baking tray with a palette knife and transfer to a chopping board. Slice into little bars measuring approximately 3x5cm, or however desired. Dust with sugar and leave to cool.

8. For the caramel, line a 20x30cm baking tray with baking paper. Warm the cream in a small saucepan, without allowing to boil.

9. Put the sugar, butter, salt, glucose and milk in a large saucepan over a medium-high heat, stirring with a wooden spoon until the butter has melted and the sugar has dissolved.

10. Begin whisking the caramel, and once it reaches 100C, make sure you continue whisking until it reaches 153C. At 153C, remove the saucepan from the heat and add the cream, in thirds, whisking quickly to incorporate.

11. Pass the caramel through a sieve and pour into the prepared baking tray. Let the caramel cool and refrigerate for at least 4 hours.

12. Remove the caramel from the tray and slice into 3x5cm rectangles, or whatever size the bars of shortbread are.

13. For the chocolate layer, break the chocolate into a bowl over a small pan of simmering water and heat until melted. Stir in the butter.

14. To assemble, top the shortbread pieces with the caramel slices and cover with the melted chocolate. Leave for a few minutes before transferring to the fridge for 30 minutes to set.