Rhubarb and Elderflower Cake

Ingredients:

For the roasted rhubarb:
400g trimmed rhubarb, cut into 4-5cm slices
110g caster sugar
finely-grated zest and juice of ½ lemon
2 tbsp elderflower cordial

For the cake:
115g unsalted butter, at room temperature, plus extra for the tins
95g whole, skin-on almonds (or use blanched or ground almonds)
200g golden caster sugar
finely-grated zest of 1 lemon
3 eggs, 2 whole and 1 white only
1 tsp vanilla extract
1 tbsp elderflower cordial, plus extra for brushing
100g plain flour
1 tsp baking powder
½ tsp bicarbonate of soda
130g full-fat natural yogurt
elderflowers, rinsed and patted dry, to garnish (or rose, lilac, geranium or peony petals)

For the elderflower cream:
300ml double cream
2 tbsp elderflower cordial
100g full-fat natural yogurt

Method:

Pre-heat your oven to 200C (180C fan/400F/gas mark 6). Butter the sides of two 20cm (4 in) diameter cake tins and line the bases with baking parchment.

To roast the rhubarb, line a high-sided baking tray with baking parchment, add the rhubarb, then top with the sugar, lemon juice, zest and cordial. Cover with foil and roast in your pre-heated oven for 25 mins until soft. Remove from the oven and reduce the temperature to 190C (170C fan/375F/gas mark 5). Strain the rhubarb from the poaching liquor, reserving the syrup.

Tip the almonds into the bowl of a food processor and blitz until ground (if using whole almonds), whilst still retaining some texture.

Put the butter in the bowl of a stand mixer fitted with a whisk attachment (or use an electric whisk) and cream it on medium speed for 2 minutes, then, using a rubber spatula, scrape down the butter from the sides of the bowl, then tip in the sugar and lemon zest. Turn up the mixer speed slightly and continue whisking for 5 mins until light and fluffy. Turn the mixer speed down slightly, then add the two whole eggs, the egg white, vanilla extract and cordial and mix together.

Combine the flour, almonds, baking powder, bicarbonate of soda and a pinch of salt in a bowl. Scrape the butter mixture down from the sides of the stand mixer bowl, turn the mixer to low speed – so it’s just stirring – then spoon in the flour and almond mixture in four batches, alternating with spoonfuls of the yogurt, and finishing with a batch of the flour and almond mixture. Mix until just combined, with no streaks remaining, then add half the roasted rhubarb and 1 tbsp of its syrup to the batter and fold it in.

Divide the batter evenly between the two prepared cake tins then transfer to your pre-heated oven and bake for 25-30 mins until a skewer inserted into the centre of each emerges cleanly. Remove the cakes from the oven, leave them to cool completely in the tins on a wire rack, then carefully remove from the tins.

For the filling, whip the cream to soft peaks in a bowl and fold in three-quarters of the remaining roasted rhubarb, along with the elderflower cordial and yogurt.

Set one of the cakes flat-side down on a cake stand or plate, prick it all over with a skewer, then use a pastry brush to brush the cake with a little of the elderflower cordial. Spoon on half the cream mixture, top with the other cake, and brush the top of that cake with cordial, too. Spoon over the remaining cream mixture, top with the remaining rhubarb and spoon over some of the poaching syrup. Garnish with elderflowers or edible seasonal flowers.