Monday, 7 May 2018

Rhubarb and Custard Layer Cake with Pistachio Sponge - a childhood treat revamped (gluten free)

I've been a bit lax on the blog front recently, but hopefully these Rhubarb and Custard Layer Cakes will make up for the gap between recipe posts.

Born out of a manic larder clear-out, they were inspired by the need to use up ingredients near or past their 'best before' date..... In this case, a huge (and rather expensive) bag of raw pistachio nuts which I bought in bulk before Christmas when making Pistachio Marzipan and half a tub of Birds Custard Powder.

Originally, I was going to combine flavours using some Kirsch-soaked Morello Cherries that I also found lurking, but when I popped into the garden the other day, I found vast quantities of rhubarb that needed harvesting...... and since the cherries were well-preserved in their alcoholic bath and would no doubt survive a little longer, I decided to go for a classic combo of 'rhubarb and custard'.

It's funny.... as a child I hated rhubarb. Miss GF gives it a wide berth too, but as I have got older, I have grown to love its tartness, especially when off-set by something a little sweeter. I don't know..... Is it one of those flavours that you 'grow into'? What's your experience? Do your kids love it or hate it?

My dislike of rhubarb strangely didn't extend to the old-fashioned (or should that be 'retro') rhubarb and custard boiled sweets and this classic marriage of sharp against creamy sweetness continues to hold nostalgic joy to my tastebuds.

The pistachios didn't obviously fit into the trip down memory lane..... I am not sure pistachios featured much in my culinary explorations until I was in my twenties, but as there was a huge stash hiding in the larder, I decided to add a bit of a modern twist and make a pistachio sponge to accompany my pink and yellow foray into childhood.

I used my tried and tested Best Gluten Free Vanilla Sponge recipe as a base and simply tweaked it by subbing the ground almonds from the original recipe with home-ground pistachio flour. It worked a treat, with the pistachios adding not only a slightly sticky moistness to the sponge, but also a subtle green hue.

Having stewed down the rhubarb, I confess I did add a tiny hint of red food colour to brighten the appearance of the compote. The custard was bog-standard Bird's ready-to-make, but with a slightly heavier weighting of custard powder to ensure a thickness that would work as a a layer of filling.

The finished cakes are a bit of a triumph (if I say so myself). All the flavour memories of sucking on Rhubarb and Custard sweets, married with rich, soft, nutty pistachio sponge. If you don't fancy pistachio cake, or haven't got a load of pistachios going wanting, this Rhubarb and Custard Layer Cake would work perfectly with your favourite vanilla sponge (you could try my Best Gluten Free Vanilla Sponge), or use a Victoria Sandwich recipe.

As for Miss GF...... Well she couldn't be left out of this pistachio cake fest (and I had made rather a lot of cake batter on account of having so many nuts to use up), so I made her an alternative (and rather delicious) Custard and Raspberry Jam cake...... Way too tempting!

Other Rhubarb or Pistachio Recipes on Gluten Free Alchemist
Rhubarb Curd
Rhubarb No Churn Ice Cream
Rhubarb, Blueberry & Honey No Churn Ice Cream
Rhubarb-Strawberry Meringue Pie
Rhubarb & White Chocolate Eclairs
Strawberry, Rhubarb & Pomegranate Jam
Pistachio 'Macaroons' with Rose & Crushed Raspberry Mascarpone Cream
Pistachio Soft Nutty Cookie Mounds
BBQ Swordfish with Lime, Pistachio & Coriander
Pistachio, Orange & Raspberry Fondant Fancies
Lime & Pistachio Pastry
Pistachio, Hazelnut, Apricot & Apple Biscotti
Pistachio & Vanilla Shortbread Cookies
Pistachio, Lime & Olive Oil Cake with Blackcurrant Drizzle
Pistachio Marzipan
Naturally Sweet Raw Green Smoothie

I am sharing my Rhubarb and Custard Layer Cake with Pistachio Sponge with the following linkies :

Baking Crumbs - This month being guest-hosted by Jo's Kitchen Larder on behalf of Only Crumbs Remain
Cook Blog Share with Hijacked By Twins
Free From Fridays with Free From Farmhouse and Le Coin De Mel

Brilliant Blog Posts with Honest Mum
Got To Be Gluten Free with myself and Glutarama
Bake of the Week with Casa Costello and Mummy Mishaps

Love Cake with Jibber Jabber who is this month celebrating the royal wedding. Okay.... so this is not exactly a wedding or celebration cake, but Rhubarb & Custard is so iconically British, I think that Meghan needs to try it!

Inheritance Recipes with Coffee & Vanilla and Pebble Soup
Recipe of the Week with A Mummy Too

Cook Once Eat Twice with Searching for Spice
Fiesta Friday with Angie and Zoale

Rhubarb and Custard Layer Cake (makes 1 x 9 inch cake or 12 mini sandwich cakes and a 7 inch sandwich)


Pistachio Sponge
320g gluten free plain flour blend (I used GFA Blend A from this post)
160g pistachio flour (raw, shelled pistachios home-ground to a powder)
1 teaspoon xanthan gum
2 teaspoons GF Baking powder
1 teaspoon bicarbonate of soda
½ teaspoon fine sea salt
330g/ml milk
1½ tablespoons white wine vinegar
170g unsalted butter - softened
360g caster sugar
2 teaspoons vanilla extract
3 large eggs (room temperature) - beaten together in a bowl

Thick Rhubarb Compote
3 to 4 stalks fresh rhubarb - cut into small pieces
large spoonful golden caster sugar
optional drop of red food colour

Custard Filling
45g GF custard powder (I used Birds)
2 to 3 tablespoons caster sugar
1 pint full fat milk

Icing Sugar to decorate


  1. Sponge : Base line the cake tins with baking paper and pre-heat the oven to 180 C/350 F/Gas 4.
  2. Weigh and mix together the flour blend, pistachio flour, xanthan gum, baking powder, bicarbonate of soda and salt and set aside (I weigh into an airtight container and shake vigorously to blend). 
  3. Using a jug, mix together the milk and vinegar and set aside for 10 minutes (the mixture will become slightly lumpy as it turns into buttermilk).
  4. In a large bowl, cream together the butter, sugar and vanilla extract until pale and fluffy.
  5. Gradually add and beat in the eggs a little at a time.
  6. Gently fold in about a third of the milk mix followed by a third of the flour mix and repeat in thirds until all the dry mix and liquid have been just incorporated into the cake batter. Be careful not to over-mix.
  7. Spoon the batter into your prepared tins (about two-thirds full) and smooth the tops.
  8. Bake for about 15-20 minutes (small cakes) and 25 to 35 minutes (larger cakes) until the top springs back and a skewer inserted into the centre comes out clean.
  9. Remove from the oven and leave to cool in the tins for about 10 minutes, before turning onto a wire rack to cool completely.
  10. Rhubarb Compote : Place the chopped rhubarb and sugar with a tablespoonful of water in a saucepan over a medium heat on the hob. Bring to a slow simmer, frequently stirring until the sugar dissolves and the rhubarb has softened and disintegrated. 
  11. Continue to simmer, stirring frequently until the liquid has reduced and you have a thickened rhubarb compote. 
  12. Add a drop of colour if using and stir through thoroughly.
  13. Set aside to cool completely (stirring occasionally).
  14. Custard filling : Mix together the custard powder and sugar in a medium saucepan, add a few spoons of milk and blend together into a smooth paste. Do not turn on the heat at this stage.
  15. Gradually add the rest of the cold milk, stirring until you have a smooth liquid.
  16. Over a low heat, very gradually bring the custard to a simmer, stirring continually to prevent any lumps forming. As the custard approaches simmer point it will begin to thicken and at this stage, it will be important to stir vigorously to ensure it remains smooth. 
  17. Once the custard has begun to gently bubble, remove from the heat and pour into a bowl. Continue to stir as it begins to cool to avoid a skin forming, or place a piece of clingfilm over the bowl in contact with the surface of the custard.
  18. Once the custard is cool, whip with a whisk to lighten slightly.
  19. Putting it all together : When ready, cut the small cake in half or use the larger sponges as individual layers. Spread a thick layer of rhubarb compote on the base layer and a thick layer of custard on the underside of the top layer and gently sandwich together.
  20. Sprinkle the top with icing sugar.
Gluten Free Alchemist © 2013-18 unless otherwise indicated


  1. Really like the sound of the flavours you have used and they look so pretty.

    1. Thank you Cat. I think there is something about the contrasting colours of rhubarb and custard which make them look extra tempting. x

  2. Beautiful retro flavours! I absolutely adore this combination and rhubarb in its own beauty but my kids stay clear lol and no cake containing rhubarb is going to temp them. I still have my hopes for the future though as they tastes mature, fingers crossed. :) Love the perfect portion size of mini cakes and the pistachio sponge sound so good too. And then rhubarb compote and lovely thick custard... Yum! Thanks for sharing with #BakingCrumbs :) x

    1. Thanks Jo. You're welcome.
      Kids eh?! No amount of persuasion will tempt Miss GF either...... I don't know what it is about rhubarb that makes them steer clear..... or why/when we decide to love it when we are older.... Mysteries! x

  3. This sounds so tasty! Thank you for sharing with us over at Fiesta Friday!

  4. My mum made sponge cakes so I would love these - rhubarb and custard is something we had as kids - I confess I didn't love it as much as the rhubarb and custard cartoon about the dog and cat - I think Sylvia loves rhubarb and custard much more than I did as a kid and would love these.

    1. Oh gosh..... I'd forgotten about the Rhubarb and Custard cartoon.... I used to love that too!
      It is good to hear that Sylvia is breaking the childhood flavour rules! Mind you, from what I read over at GGG, she has an amazing palate (certainly compared to my childhood anyway!).... x

  5. I hope Ms Markle has been instructed in the importance of an English afternoon tea! These would fit in perfectly with a Royal Wedding themed celebration buffet. I'm so glad the pistachios didn't go to waste. We all love rhubarb which is a good job as it is taking over our allotment at the moment!

    1. I hope so too Ness! Afternoon Tea is definitely one of those quintessentially English traditions that must remain important. In fact..... Miss GF was at the Palace just last week, enjoying one with the Duke of York..... I have it on her good authority though that the gluten free banana cake she was served is no where near as good as mine! Ha! x

  6. This sounds amazing!! I also did not like rhubarb as a child and only here in UK I tried it again... Now I love it, especially in accompaniment of custard.
    Thank you for submitting it to the Inheritance Recipes :)

    1. Thanks Margot. You're welcome. I have to agree that rhubarb is at its best with custard! x

  7. these look so adorable Kate. I did notice on twitter just now that you have used a pistachio sponge too! wow - what great flavour combinations you have used in this recipe! I bet these are so delicious too. perfect for an afternoon tea or a right royal knees up ;)
    thank you for sharing with #bakeoftheweek x

    1. Awww thank you Jenny. You're welcome. I do love a good pistachio sponge..... although I was shocked when I last bought pistachios at just how expensive they have become..... there was NO WAY those were going to waste! x

  8. I loved rhubarb as a kid and still do! I think your little cakes look so tasty and so cute too. Thanks so much for sharing with #CookOnceEatTwice

    1. Oh wow! I think you may be in a minority Corina. But I am pleased to hear that you stepped away from expectation and enjoyed the pink stuff! x

  9. great minds think alike ;) i've a rhubarb and custard cake on my blog too this week! Love this gluten free version though - great for our gluten free friends and guests here. #recipeoftheweek

    1. Great minds indeed! I must pop over and have a look..... I love perusing other people's creativity! x

  10. I loooove these rhubarb mini beauties.I too have rhubarb that I need to use up tomorrow.I wish I could produce something so blinking clever.x

    1. Ha ha! Thanks..... Your stuff is way cleverer than this! x

  11. Kate, your Rhubarb and Custard Layer Cakes look to die for! I love rhubarb, and I guess the tartness of it must be softened a bit with the custard. You're a genius, my lovely! Thanks for joining in with #FreeFromFridays.

    1. Aww thanks Mel. Way too kind.... but they were rather yummy xx

  12. They look so tempting and I am loving the flavour combination! I really like the new look of the blog too!

    1. Thank you Kat on both counts. The blog is a work in progress, but so far, I am happy with the changes x

  13. Oooh we love rhubarb and ours is about ready for picking! These look and sound delicious! Thank you for sharing with #CookBlogShare x

  14. I love rhubarb Kate, and always have. Mum often made us rhubarb crumble & custard when we were young - it always got a thumbs up from us so I can imgine how good these dinky cakes must have tasted with the creamy custard contering the sharp rhubarb - yum! Thankyou for sharing with #BakingCrumbs,
    Angela x

    1. Thanks Angela. It is such a British classic.... I think everyone has tales of rhubarb and custard, whether they love it or not! x


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