Rhubarb & pistachio polenta cake

This mash-up recipe from 3 different sources came about for a dinner party – I was lucky that it worked so well trying it for the first time with guests due! I’m typing this up whilst polishing off the last of the rhubarb syrup on my breakfast 🙂

Photo 30-04-2017, 13 41 20

The cake had a beautiful crumb, slight tartness from the rhubarb, but the crystallised pistachios on top really made it special for me. My one reservation with the recipe was that the cake batter was incredibly liquid so most of the rhubarb sank to the bottom – no pretty pink swirls for me! It was rose petals to the rescue.


  • As I was using some rather chunky green rhubarb stalks I followed Nigel Slater’s advice from his Rhubarb Cinnamon Polenta Cake recipe to chop and roast them before making the cake – in doing so you get a gorgeous syrup to use for serving.
  • The cake itself was based on Emma Hatcher’s Rhubarb and Polenta Cake – from her book of low FODMAP recipes – perfect as I needed a gluten and dairy free recipe. I wanted to use pistachios and darker sugar for my version, but loved the addition of complex olive oil to the mix.
  • Finally, the finishing touch was the crystallised pistachios from Martha Collison’s Pistachio & Rose cake in Waitrose magazine. It’s a small wonder that any of these little wonders actually made it onto the cake.

Photo 29-04-2017, 16 20 47

Rhubarb & Pistachio Polenta Cake with Crystallised Pistachios


  • 400g rhubarb, chopped into thumb-sized pieces + 2 heaped tbsp sugar
  • 120ml almond milk
  • 1/2 tsp apple cider vinegar
  • 120g coarse polenta
  • 70g ground pistachios (whizzed until fine with the flat nutribullet blade)
  • 50g buckwheat flour (check this is labelled gluten free if making for a coeliac)
  • 2 tsp baking powder
  • 1/2 tsp bicarbonate of soda
  • 1/2 tsp sea salt
  • 150g soft dark brown sugar
  • 120ml extra virgin olive oil
  • 2 eggs
  • 1 tsp vanilla extract

For the crystallised pistachios:

  • 50g caster sugar
  • 50g pistachios


  1. Preheat the oven to 180°c. Oil and line an 8 inch/20cm cake tin.
  2. Cut each rhubarb stalk into three or four pieces and put them in a baking dish. Scatter over the sugar and 3 tbsp water, and bake for 30 minutes until the rhubarb is soft but still retains its shape. Remove the fruit from the dish and put it in a colander to drain. Reserve the juice to serve with the cake.
  3. Whilst the rhubarb is cooking, prepare ‘buttermilk’ by combining the almond milk and apple cider vinegar.
  4. When the rhubarb is cooked, prepare the cake batter. Lightly mix together the polenta, ground pistachios, buckwheat flour, baking powder, bicarbonate of soda and salt.
  5. In another bowl, combine the sugar, olive oil, buttermilk mixture, eggs and vanilla. Pour the wet ingredients over the dry and gently fold a couple of times.
  6. Spoon the batter into the cake tin and gently drop the dried rhubarb pieces into the batter.
  7. Bake for 30–35 minutes or until risen and firm to the touch.
  8. While the cake is baking, make the crystallised pistachios. Place the sugar and 50ml of cold water into a small saucepan and bring to the boil. When the sugar syrup just starts to colour around the edges, remove from the heat and tip in the pistachios. Beat rapidly with a balloon whisk so the syrup crystallises around the pistachios, then tip onto a sheet of baking parchment to cool completely. When cool enough to handle, pull apart to separate the nuts.
  9. Allow the cake to cool for 10 minutes in the tin, before removing to a wire rack to cool completely.
  10. Decorate with a drizzle of icing or syrup, the pistachios and dried rose petals (optional).

We served ours with (dairy free) custard, because rhubarb!

Photo 30-04-2017, 13 45 39Photo 30-04-2017, 13 45 19Photo 29-04-2017, 16 21 33

2 responses to “Rhubarb & pistachio polenta cake

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