Roast rhubarb & geranium sugar cake

Method

1. Preheat the oven to 160°C.

2. Trim the rhubarb stalks. Slice the rhubarb into 2.5cm pieces and arrange in a single layer in a 45 x 30cm (18 x 12 inch) non-reactive ovenproof dish. Scatter the sugar over the rhubarb and leave to macerate for 1 hour or more, until the juices start to run.

3. Preheat the oven to 200°C.

4. Cover the rhubarb with a sheet of parchment paper and roast in the oven for 10 minutes. Remove the paper and continue to roast for 10 minutes, depending on the thickness of the stalks, until the rhubarb is just tender. Keep a close eye on the rhubarb as it can disintegrate very quickly, it may only take 10 minutes in total. Cool.

5. Line the base of a 30 x 20.5 x 2cm (12 x 8 x 3/4 inch) cake tin with parchment paper, allowing it to hang over the sides. If available, arrange 6-8 sweet geranium leaves over the base.

6. To make the sponge base, combine the soft butter, sugar and flour in the bowl of a food processor. Whizz for a second or two, then add the eggs and stop as soon as the mixture comes together. Spoon the mixture over the base of the tin as evenly as possible (over the sweet geranium leaves). Arrange the rhubarb carefully over the sponge mixture. Bake for about 50 minutes.

7. Meanwhile, whizz the sweet geranium leaves with caster sugar in a food processor. Spread over a baking tray and set aside at room temperature to dry out.

8. When the cake is fully cooked, the centre of the cake should be firm to the touch and the edges slightly shrunk from the sides of the tin. Leave to rest in the tin for 4–5 minutes, sprinkle with sweet geranium sugar and cut in portions.

9. Serve with crème fraîche or softly whipped cream.