SEA SALT CARAMEL CAKE

THIS classic sponge has a lovely light crumb thanks to the addition of buttermilk. The feathered salty caramel topping looks simple, but takes a little skill to master.

Makes 1 cake

For the sponge

250g (9oz) unsalted butter, softened 300g (10½oz) golden caster sugar 4 medium eggs 1 tsp vanilla extract 300g (10½oz) self-raising flour Good pinch of salt 5 tbsp buttermilk, at room temperature

For the filling and frosting

250g (9oz) unsalted butter, softened 450g (1lb) dark muscovado sugar 175ml (6fl oz) double cream 250g (9oz) icing sugar, sifted ¼-½ tsp sea salt flakes 100g (3½oz) dark chocolate (70 per cent cocoa solids), chopped

1 Preheat the oven to 180c/160c fan/ 350f/ gas 4. Grease and line the tins with butter and baking paper.

2 To make the sponge, put the butter into a large mixing bowl and beat well with a wooden spoon or with a whisk attachment until creamy. Gradually beat in the caster sugar, then scrape down any mixture from the sides of the bowl and beat for a further 2 minutes or until well mixed and lighter in colour.

3 Break the eggs into a separate bowl, add the vanilla extract and beat with a fork just until broken up, then gradually beat into the butter mixture, beating well after each addition. Add a tablespoon of the self-raising flour with each of the last two additions of egg to prevent the mixture curdling.

4 Sift remaining flour and salt into the bowl. Add buttermilk and gently fold it all together using a large metal spoon.

5 When thoroughly combined, divide the mixture among the three prepared tins (for this cake it is best to do this by weight for accuracy) and spread evenly.

6 Bake the cakes for 22– 25 minutes until the sponges are golden. Check the cakes are cooked — they should start to shrink away from the sides of the tins and spring back when lightly pressed in the centre with your fingertip. Check the cakes after 20 minutes and turn the tins round if they are not baking evenly.

7 Run a round-bladed knife around the inside of the tins to loosen the sponges, then leave to cool and firm up for 2 minutes before turning onto a wire rack.

8 While the sponges are cooling, make the filling and frosting. Put 175g (6oz) of the butter into a heavy-based medium pan with the dark muscovado sugar and double cream. Set over a low heat and stir with a wooden spoon until melted and lump-free, then increase the heat and bring the mixture to a boil, stirring constantly. As soon as it boils, turn down the heat so that the mixture gently simmers for 5 minutes, stirring frequently.

9 Pour into a heatproof mixing bowl and whisk while slowly and gradually beating in the sifted icing sugar. Continue beating after all the sugar has been added, for about 8 minutes or until the mixture is fluffy and cooled to barely warm. Gradually beat in the remaining 75g (2¾oz) soft butter (if the mixture is too warm it will melt the butter and the mixture will be too soft). Sprinkle over ¼ teaspoon of the salt and stir in with a plastic spatula. Taste and add a little more salt as needed. Cover the bowl and leave on the worktop.

10 Put chopped dark chocolate into a small heatproof bowl and set over a pan of steaming hot but not boiling water — don’t let the base of the bowl touch the water — and melt the chocolate gently, stirring occasionally. Remove the bowl from the heat, stir again, then spoon two-thirds into a separate bowl and fold in 250g (9oz) of the caramel mixture. Put to one side until spreadable. Cover the rest of the caramel and put to one side.

11 Set one sponge crust-side down on a serving platter and spread with half the chocolate caramel. Cover with another sponge, crust-side up, and spread with the rest of the chocolate caramel. Place the third sponge on top, crust side up. Using a palette knife, thickly spread the caramel over the top and sides of the cake to completely cover. If the caramel mixture has become too firm to spread easily, gently warm it over a pan of steaming water, and stir until smooth and spreadable.

12 Spoon remaining chocolate into the piping bag and snip off the end to make a writing tip about 3mm ( 1/ in) 8 across. Hold the bag vertically over the cake and, starting in the centre, pipe a spiral of chocolate on top of the cake without touching the surface. Work quickly and don’t worry about the odd wobble.

13 Then gently draw the tip of a cocktail stick through both the chocolate spiral and the caramel frosting, from the centre to the sides at six regular intervals, to make the first set of lines. Then draw the cocktail stick back from the edge towards the centre to make lines in between the first set of lines.

14 Leave the finished cake to firm up for about 3 hours, uncovered, before serving.