For the lavender sponge
- 6 eggs
- 175 g (6 oz) caster or granulated sugar
- pinch of salt
- 150 g (5 oz) plain flour
- 2 tsp lavender buds, finely chopped (off the stems)
- 125 g (4½ oz) butter, melted, plus extra for greasing
For the rhubarb curd
- 550 g (1 lb 3 oz) rhubarb, cut in to 1cm (½in) slices (weigh when sliced and trimmed)
- 200 g (7 oz) caster or granulated sugar
- 75g (3 oz) butter
- 3 eggs, whisked
- To decorate
- icing sugar
- Preheat the oven to 180°C (350°F), Gas mark 4. Line the base of three 18cm (7in) cake tins and butter the sides.
- To make the sponge, place the eggs, the sugar and the salt in the bowl and, using an electric whisk, beat for 5–8 minutes until tripled in volume, light and fluffy. Sift in the flour and fold into the light mousse-like mixture with the lavender and the melted butter, working quickly so that too much air does not escape.
- Divide the cake mixture into the three tins and place in the oven. Bake for 22–25 minutes until light golden and a skewer inserted into the centre comes out clean. Take out of the oven and let sit in the tin for a few minutes before taking out and cooling on a wire rack.
- Next, make the curd. Place the rhubarb and 50g (2oz) of the sugar in a saucepan on a medium heat, stirring every so often. Cook for about 5–6 minutes until the rhubarb has softened, broken up completely and the mixture has thickened to a pulp.
- Pour into a sieve sitting over a bowl and push the mixture through the sieve into the bowl, making sure to scrape the underside of the sieve to get every last bit.
- Next, place the butter in the cleaned saucepan on a low-medium heat and allow to melt. Take off the heat just while you add in the eggs, rest of the sugar and the rhubarb purée. Put back on a low heat and stir all the time for about 2–3 minutes until thickened. Take off the heat, tip into a bowl and allow to cool.
- When ready to assemble, place one cake (save the cake with the best-looking top for the top) upside down on a plate or cake stand. Place half of the curd on top and spread it out (I like to allow the curd to drip slightly over the edges). Put the next cake, right side up, on top, then cover with the second half of the curd, as before. Finally, top with the third (and best-looking) cake. Dust with icing sugar and decorate with some more lavender if you’d like.