Sure, it's incredibly pretty, but rhubarb's sharp taste and tendency to soak everything it comes across with its juices makes it a potentially tricky ingredient to bake with. However, provide it with enough sugar, and make sure you harness those juices, and you've got one of the most thrilling flavours created by Mother Nature. This cake is a perfect example of this: vanilla, blood orange and pistachios co-operate beautifully together here, allowing the rhubarb to be the star of the show but not exactly hiding in the shadows themselves. If you're using unforced, green rhubarb, be sure to add extra sugar.
400g rhubarb, sliced into 4cm lengths
4 tbsp caster sugar
Zest of 2 blood oranges
250g room temperature unsalted butter
250g soft brown sugar
150g ground almonds
4 medium eggs
50g plain flour
1 1/2 tsp baking powder
Seeds from 1 vanilla pod
Preheat the oven to 190C/fan 170C/325F and grease and line a 22cm springform cake tin. Place the rhubarb in a bowl and toss with the sugar and orange zest, and put to to one side to marinate for a moment.
Whiz 125g of pistachios in a food processor until finely ground and roughly chop the remaining 25g. Put both to one side for the moment.
Beat the butter and sugar together with a handheld electric hand whisk for 3-4 minutes until pale. Start adding the eggs, one by one, waiting for the previous one to be mixed in before adding the next. Fold in the ground pistachios, 125g ground almonds, flour, baking powder, vanilla seeds and a pinch of salt.
Toss the rhubarb in the remaining 25g ground almonds. Spoon half the cake mixture into the tin, spreading it right to the edges. Arrange just less than half the rhubarb on top, keeping it way from the edges of the tin. Spoon over the rest of the cake mixture, spreading it so it covers the rhubarb. Arrange the rest of the rhubarb on top, again keeping it away from the edges. Sprinkle over any remaining sugar and scatter with the chopped pistachios, lightly pressing everything in. Bake for 50-60 minutes, covering the top with a sheet of baking paper if it starts to darken too much, until an inserted skewer comes out clean. Leave to cool, then serve with creme fraiche, cream or custard.