Pistachio and Lemon Traybake

A wonderfully moist, dense textured sponge adorned with a whipped lemon custard and swirls of lemon curd

Pistachios are having a moment online, with the whole viral Dubai chocolate craze. But with the plethora of pistachio/chocolate content, I wanted to divert from the herd culture and do something a bit different. Also, the popularity of pistachios mean that they are a fair bit expensive in comparison to some other nuts, and I have tried to create a recipe that is accessible to many, and bake this as a 20cm traybake, rather than a layered cake.

Whilst traybakes are seen as more rustic, novice bakes relative to their fancier tiered cake counterparts, I think that these can be equally pretty. Plus they have the added benefit of easily being able to feed a crowd. If you need to feed a crowd, you can double the recipe, bake it in a 22cm by 33cm tray and increase the baking time for a further 10 minutes.

The pistachio and lemon flavours pair particularly well together. The cake itself is more pistachio than lemon, with only a slight hint of zest in the cake batter. The lemon flavour gets layered on in the form of the lemon syrup which is brushed onto the cake after baking. This not only adds depth of flavour to the cake, but also keeps the sponges moist (why do people not like using that word?).

The whipped lemon custard is really special, I feel, and is a nice alternative to the more conventional cream cheese icing, or worse cloyingly sweet buttercream. It is almost like a whipped cream, but with a more subtle lemon flavour added. Finally, I like to finish this off with swirls of lemon curd and a sprinkling of chopped pistachios around the border of the cake. It takes a very ordinary traybake to something instagram-worthy.

If you make this recipe, please share it with me by tagging me on Instagram @adventureswithsugar or on Facebook at Adventures with Sugar. Please also leave a comment below to let me know how you got on with the recipe.

FOR THE PISTACHIO AND LEMON TRAYBAKE

• 175g butter, cubed at room temperature
• 175g caster sugar 
• 2 Tablespoons lemon zest
• 3 large eggs, at room temperature
• 1 teaspoon vanilla essence/extract
• 1 1/2 teaspoons almond essence 
• 60ml extra-virgin olive oil
• 50g sour cream 
• 2 Tablespoons lemon curd 
• 1/2 teaspooon baking powder
• 100g ground pistachios
• 40g ground almonds
• 130g self-raising flour 

METHOD

1. Preheat the oven to 180 degrees Celcius and grease and line the base and sides of the tin with baking paper, a 20cm square tin. 
2. Rub the lemon zest and caster sugar together, with your fingertips. This releases all the oils within the zest and smells incredibly fragrant.
3. Then add in the butter, and cream with the sugar and lemon zest. Cream the ingredients for around 5 minutes until the mixture is smooth and the butter has turned a paler shade, turning almost cream from the initial yellow.
4. Add the eggs in, one at a time. Add the next one only once the previous has been fully incorporated. The mixture will look fairly curdled at this point, but it will all come together at the end when the flour is added.
5. Add in the vanilla, almond essence, olive oil, sour cream and lemon curd. Beat to combine all of the ingredients. The mixture will still look curdled, but that is still fine.
6. In a separate bowl, sift the self-raising flour and baking powder together, then add in the ground almonds and ground pistachios. Aerate the batter with a whisk to ensure that all the nuts are evenly distributed.
7. Slowly add the flour and nut mixture to the wet ingredients and gently fold by hand to combine, until their are no streaks of flour remaining and the nuts are evenly dispersed through the batter.
8. Pour into your baking tin and bake for 30 – 35 minutes, until the cake is golden brown and a skewer inserted comes out clean. Begin checking for doneness at around 25 minutes.
9. As soon as the cake comes out of the oven, begin working on the syrup.
10. Once the cake comes out of the oven, let it cool in the tin for 10 minutes, before loosening the edges with a butter knife and inverting it onto a cooling rack. The bottom of the cake should now be facing upward so that you have a smooth top.

FOR THE LEMON SYRUP

• 80g icing sugar
• 40g caster sugar
• 30ml water
• 30ml fresh lemon juice
• 50g lemon curd

METHOD

1. Once the cake has come out of the oven, and is cooling in the tin, get to work on the syrup.
2. Simply place all the ingredients in a medium heat-proof saucepan and whisk to combine.
3. Then gently heat until the sugar is just dissolved. You are not trying to boil the syrup like a conventional recipe – so the syrup will only be warm to touch.
4. I find that the best way to brush the cake is to place the cooling rack over a larger tray, so you can catch the syrup which drips off, scrape it off the tray and re-brush it onto the cake.
5. Brush half of the syrup on the top and the four sides of the cake and let it soak in. Then repeat until all the syrup has been used up.
6. Allow the cake to cool for a further 30 minutes. Then, if you want to lock in the moisture, wrap the cake in clingwrap/plastic wrap and leave to cool completely.

LEMON CURD CREAM

• 125ml full cream milk
• 1 teaspoon vanilla bean paste
• 2 egg yolks
• 50g caster sugar
• 10g cornflour (1 1/2 tablespoons)
• 5g plain flour (3/4 teaspoon)
• 180ml whipping cream
• 2 – 3 Tablespoons lemon curd, to taste

METHOD

1. Once the cake is in the oven, begin making the lemon curd cream.
2. Place the milk in a medium heat-proof saucepan and heat the milk on medium heat, until the milk is just simmering, but not boiling over.
3. Whilst the milk is heating, place all the ingredients, except the whipping cream and lemon curd, in a bowl and whisk vigorously to combine. It may initially seem like there is too much dry ingredients relative to the egg yolks, but eventually it will come together.
4. Take the simmering milk off the stove and slowly stream in half of the milk into the egg mixture, tempering the eggs so they do not scramble. Then once eggs have adjusted to the warmer temperature of the milk, pour in the remaining milk and give everything a quick whisk to combine.
5. Return this custard mixture to the saucepan on medium heat, and whisk constantly until the custard begins to thicken completely. Remove from the heat, scrape into a bowl. The custard is quite thick, but you have not done anything wrong, it is going to get whipped with the cream later.
6. To quicken the cooling process, place a film of clingwrap/plastic wrap directly on the surface of the custard and place in the fridge to cool.
7. Once the custard (and the cake is cool) and you are ready to frost the cake, place the custard in a large bowl, as you will be adding the whipping cream to it.
8. Add a third of the whipping cream, and beat using a hand-held beater. This should break up the custard and begin to form a smooth cream. Do not overwhip.
9. Then add in the remaining cream and continue to whip until you have a looser cream, but still one that will hold its shape when spread on the cake.
10. Add in the lemon curd and continue to beat for a few seconds, tasting to see how much you prefer. I prefer to go with 2 tablespoons, as more lemon curd gets swirled on the top after.

TO ASSEMBLE

• 20g pistachios, roughly chopped (optional)
• 20g lemon curd

METHOD

1. By now, you will have a cooled cake which is bathed in the delicious lemon syrup and a delicious, lightly lemony cream.
2. Begin by spreading the cream onto the cake and creating little swirls on the top. It is easiest to spread the cream with a palette knife and squaring off the edges so that it looks to be in line with the cake. The swirls are easier to create with the back of a tablespoon, so they create little dips to drop some dollops of lemon curd into.
3. Spoon on the lemon curd in little dollops all over the cake, and continue to swirl to combine. This creates a pretty marbled effect.
4. Finally, chop some pistachios by hand. I like to do this by hand so that you get more chunky pieces for texture, but you can use more finely ground if you prefer.
5. Scatter along the edge of cake, almost creating a little frame to finish off the traybake.
6. You could also arrange a few edible flows on one of the corners of the cake, for an extra special touch, but I did not have any.

Recipe by adventureswithsugar.com