The Technical Challenge for the 2021 Bake Off’s semi-final was set by Prue, and saw the bakers making a Sablé Breton cake. A thick biscuit layer, topped with raspberry jam, a pistachio crème mousseline, and decorated with fresh strawberries, raspberries, meringue kisses and chocolate curls. Just a few elements for a semi-final Technical, eh? 😉 So let’s get cracking!
*I’d just like to apologise for the slightly shocking pictures in this post… Unfortunately we have reached the time of year where it gets dark at 3pm, so I didn’t manage to take photos while I still had natural light. So I am sorry that these pictures look a terrible – the cake at least tasted better than it looked in these, promise!*
What “special” ingredients do you need to make Prue’s Sablé Breton?
As I have found with a lot of these technical challenges, the list of ingredients is often quite substantial! Plus it often contains very unique or expensive ingredients that, even as a very keen baker, I don’t have at home and need to buy. This time it was mainly the volume and type of ingredients that made this quite a pricey cake to make: fresh raspberries and strawberries, vanilla bean paste/a vanilla pod, pistachios….
The recipe also called for using pistachio oil and pistachio extract for making the crème mousseline. I could find either in the shops, so actually had to substitute the pistachio for vegetable oil, and simply omit the pistachio extract. This meant though unfortunately that the crème wasn’t quite as intense in its pistachio flavour.
For the jam, Prue’s recipe also states that you should add pectin which should help thicken the jam. However, I just used the jam sugar and that worked fine for me. So I’d say it’s safe enough to omit.
The elements of the Sablé Breton Cake
There are a lot of different elements to this Sablé Breton cake – it was the semi final after all! Let’s go through each element in turn and I will share with you some of my tips and tricks!
SABLÉ BRETON DOUGH
The Sablé Breton biscuit dough is probably the easiest component of this bake. The method is slightly odd, not what I am used to, as egg yolks and sugar are whisked first, before adding butter and then folding in the flour. The dough is quite sticky, so just spoon it straight onto a piece of clingfilm, cover and flatten into a disk before chilling in the fridge. I also didn’t bother rolling it out with a rolling tin, but just placed it in the tin and used my hands to flatten it! Much easier and fewer dishes to wash – win, win!
MERINGUE KISSES
Meringue kisses are fairly easy to make, and I actually didn’t make any for this particular recipe! I still had some meringue kisses stored in a plastic container in my baking cupboard which were left over from the August Bake Off Box recipe for Passion Fruit Éclairs! So that at least sped up the process a little for me! The below recipe will make a lot more meringue kisses than you need, so you could always make the Passion Fruit Éclairs afterwards to use the meringues! Or just enjoy them sprinkled over some ice cream or as little sweet treats!
I also tried to add some gold leaf to the meringue kisses to decorate, but my gold leaf skills definitely leave a lot to be desired! It got stuck everywhere but on the meringues! I’ll have to practice that again another time! XD
RASPBERRY JAM
As mentioned above, Prue’s original recipe (see here), she says to use both jam sugar and pectin to help thicken the jam. I couldn’t find pectin so just made the raspberry jam without it, and it still worked. If you are feeling lazy (or don’t want to spend money on fresh raspberries and jam sugar), you could also just use a shop-bought jam!
PISTACHIO CRÈME MOUSSELINE
Crème mousseline is a crème pâtissière (French pastry cream, basically just a thick custard) but with butter added to it. So the process of making this is just like for making a crème pâtissière (check out the baking basics post here for more info), and then you just whisk in some softened butter once cooled. To give the crème mousseline a green colour and pistachio flavour, a pistachio paste is folded into the crème mousseline once cool. The pistachio paste is made by blitzing together pistachios, pistachio oil and pistachio extract, although I had to do it slightly differently (see above) as I couldn’t find the right ingredients.
The most important thing when making the crème mousseline is to not heat the milk/mix too much as this will scramble the egg, and covering the surface with clingfilm when cooling to prevent a skin from forming. It’s also important to chill the crème thoroughly in the fridge before using so that it stays on top of the Sablé Breton biscuit.
TEMPERED CHOCOLATE CURLS
In order to get a lovely shine on chocolate, you need to put it through a process of heating and cooling, called tempering. A quick and easy way to do this without a sugar thermometer, is to melt 2/3rd of the chocolate over a bain-marie, and then stirring in the remaining third afterwards to cool the chocolate down again.
To make the curls, I had to improvise and use a sturdy freezer bag in place of acetate, and a flat end of a spoon instead of a chocolate comb. I still managed to make some chocolate curls despite a lack of equipment, so that was good! You could, however, also just melt and temper the chocolate, and then pipe squiggly lines or similar on some baking parchment to decorate. Completely up to you!
More Bake Off Technical Challenges
I am absolutely obsessed with the Great British Bake Off and have challenged myself to attempt all of (or at least the ones that are “realistic” – I won’t be making pitta breads on a camp fire in the back garden!) the technical challenges from the programme! I have tried quite a few already, so make sure you check out some of the other recipes and see how I got on!
- Mary Berry’s Religieuses
- Mary Berry’s Fraisier Cake
- Paul Hollywood’s Hand-raised Chicken, Bacon and Apricot Pies
- Mary Berry’s Bakewell Tart with feathered Icing
- Paul’s Mini Pineapple Upside Down Cakes
- Mary Berry’s Frosted Walnut Layer Cake
- Paul Hollywood’s Cottage Loaf
- Mary Berry’s Homemade Jaffa Cakes
- Paul Hollywood’s Wagon Wheel Biscuits
- Mary Berry’s Victoria Sponge Cake
- Paul Hollywood’s Mini Pork Pies
- Mary Berry’s Viennese Whirls
- Prue’s Vegan Chocolate and Raspberry Tarts (S2UC Special)
- Pizza Star Bread (Junior Bake Off)
- Mary Berry’s Coffee and Walnut Battenberg Cake
- Paul’s Crusty White Cob
- Paul Hollywood’s Rainbow Bagels
- Prue Leith’s Malt Loaf
- Paul’s Jammy Biscuits
- Paul Hollywood’s Olive Ciabatta Bread Sticks with Homemade Tzatziki
- Prue Leith’s Sticky Toffee Puddings with Sesame Tuiles
- Prue Leith’s Prinzregententorte
- Paul Hollywood’s Baklava (22cm)
- Paul’s Caramel Biscuit Bars (Twix)
- Prue Leith’s Vegan Sausage Rolls
- Prue’s Sablé Breton Cake
- Paul Hollywood’s Sticky Belgian Buns
- Red Velvet Cake with Cream Cheese Icing
- Prue’s Garibaldi Biscuits with Feathered Chocolate Icing
- Paul Hollywood’s Pain au Raisins
- Paul’s Spicy Beef Tacos
- Paul Hollywood’s S’mores
- Prue Leith’s Pistachio Praline Ice Cream Cones
- Vegetable Spring Rolls
- Prue’s Vertical Chocolate, Hazelnut, and Raspberry Tarts
- Paul Hollywood’s Devonshire Splits
Prue Leith’s Sablé Breton Cake | Bake Off Technical Challenge
Recipe
INGREDIENTS
For the sablé dough:
- 170g plain flour
- 1 tsp baking powder
- ¼ tsp fine sea salt
- 125g unsalted butter, at room temperature, cubed
- 4 egg yolks
- 100g caster sugar
For the meringue kisses:
- 1 egg white
- 60g caster sugar
- pinch of salt
For the raspberry jam:
- 350g raspberries
- 120g jam sugar
- 2g pectin
For the chocolate decorations:
- 90g dark chocolate (54% cocoa solids), finely chopped
For the pistachio paste:
- 75g pistachios
- 2-3 tsp pistachio oil
- 10 drops pistachio extract
For the crème mousseline:
- 250ml whole milk
- ½ vanilla pod, split lengthways and seeds scraped out OR 1 tsp vanilla bean paste
- 4 egg yolks
- 50g caster sugar
- 35g plain flour, sifted
- 100g unsalted butter, at room temperature + cut into cubes
To decorate:
- 30 strawberries, hulled and halved
- 10 raspberries
- 2 sheets of gold leaf (optional)
You will also need:
- small piping bag fitted with a small open star nozzle
- 20cm sandwich tin, greased, then base-lined with baking paper
- 15 x 8cm piece of acetate (you could also use a sturdy freezer bag)
- chocolate comb (alternatively, use the flat end of a metal spoon or similar)
- inside tube from a kitchen roll or tall or a narrow glass
- medium piping bag, fitted with a medium plain nozzle
- small cake-decorating paint brush (if using gold leaf)
Method:
- To make the Sablé dough, sift the flour, baking powder and salt together into a bowl and set aside. Beat the butter on medium speed for 2–3 minutes, until soft and creamy.
- In a separate bowl, whisk together the egg yolks and caster sugar until thick and mousse-like, and the mixture leaves a ribbon trail when you lift the whisk. Using a wooden spoon, beat in the softened butter until fluffy. Finally, fold the flour mixture in to make a dough. Shape the dough into a rough disk and wrap the dough in clingfilm and chill it in the fridge for 1 hour.
- Next, start to prepare the meringue kisses. Preheat the oven to 120°C/100°C fan and tip the egg white into a large, clean bowl. Use and electric whisk to whisk slowly until the mixture starts to become foamy. Then increase the speed and whisk until the mixture becomes white and starts to stiffen. Continue whisking on high speed while gradually adding the caster sugar, 1 teaspoon at a time, whisking well between each addition. Add the salt and continue whisking until you have added all the sugar and the meringue is smooth, glossy, and very stiff.
- Spoon the meringue into the small piping bag fitted with a small open star nozzle and pipe small ‘kisses’ onto the lined baking sheet. Bake the meringue kisses in the middle of the oven for around 45 minutes, until they are dry and you can peal them off the baking paper easily. Remove them from the oven and leave them to cool on the baking sheet. Leave the oven on.
- To make the raspberry jam, add the raspberries and 75g of jam sugar to a small saucepan and mash with a potato masher. Place over a low heat and slowly bring the mixture to the boil. In the meantime, mix the remaining 45g of jam sugar with the pectin in a small bowl, then whisk this into the contents of the pan. Continue to boil the jam for 3-4 minutes until thick, then pass the jam through a sieve into a bowl. Set the jam aside to set until needed.
- Increase the oven temperature to 180°C/160°C fan.
- Lightly grease and line the base of a 20cm round baking tin with baking paper. Transfer the chilled dough into the tin and flatten the disk until it completely fills the base of the tin and is even. Bake in the preheated oven for 20-25 minutes until risen and golden brown.
- Meanwhile, make the chocolate decorations. Melt 60g of the chocolate in a glass bowl set over a pan of simmering water. Then remove the bowl from the heat stir in the remaining 30g of chopped chocolate to cool the mixture down again.
- Use a palette knife to spread a spoonful of the chocolate onto the acetate. If you have a chocolate comb, drag it across the chocolate from the top left-hand corner to the bottom right-hand corner to form diagonal lines. Alternatively, you could try and drag the flat end of a spoon (or similar) through the chocolate to create lines. Carefully roll the acetate rectangle until the shorter edges are just about touching and place it in the cardboard tube or tall, narrow glass. Then set aside to set.
- Next, prepare the pistachio paste. Blitz the pistachios and 2 tsp of pistachio oil in a small food processor until smooth. Add a little more oil if the paste seems too dry. Then add the pistachio extract and blitz for a further 30 seconds. Set aside until needed.
- For the crème mousseline, pour the milk into a pan and add the vanilla. Gently warm the milk until just below boiling point.
- In the meantime, whisk the egg yolks, caster sugar, and flour together in a mixing bowl until smooth and paler in colour. Once the milk is hot, pour it into the egg mixture in a slow and steady stream, while whisking constantly.
- Return the mix back to the heat and whisk for 2-3 minutes until the mixture has thickened. Transfer the crème to a shallow bowl and place a piece of clingfilm on top to prevent a skin from forming. Leave the crème to cool at room temperature for 10, before chilling it in the fridge for 60 minutes or until needed.
- Remove the chilled crème from the fridge and transfer to a mixing bowl. Add the softened butter, a little at a time, and whisk in with an electric (or hand-held) whisk until smooth and fully incorporated. Then fold in the pistachio paste and spoon the crème mousseline into a piping bag fitted with a plain nozzle. Chill the cream in the fridge until needed.
- To make the glaze for the fruit, gently warm 2 tbsp of the set jam with 3 tbsp of water in a small pot and whisk until smooth and just below boiling point. Set aside until needed.
- To assemble the sable Breton cake, spread the remaining jam over the baked sable biscuit, leaving a 1.5cm border around the edge. Pipe the crème mousseline in a spiral over the jam, working from the outside into the middle. If the crème seems a bit soft, chill the cake in the fridge for 15 minutes.
- Arrange the strawberries and raspberries on top of crème mousseline layer. Then use a pastry brush to glaze the fruit with the glaze.
- Finally, use a small cake-decorating paint brush to top 12 of the meringue kisses with gold leaf and place on top of the sable Breton. Carefully peel the chocolate spirals off the acetate and lay them on top to finish.
