Chocolate Salted Sponge

Sweet-yet-salty is quite the cuisine trend du jour (I'm sure you're all familiar with Nigella Lawson and her salted caramel), but it's more than just a fad - using salted butter in this cake helps to bring out the cocoa flavour, giving a cake with an intense, rather than sickly, chocolate flavour.

I first made this cake as a Valentine's present, hence the heart shape, but it works spectacularly well as a triple-layer celebration cake - just add on half the ingredients again to make three sponges and a third more buttercream. 

Ingredients

For the sponge:

175 caster sugar

175g salted butter (room temperature)

3 eggs

175g self-raising flour

2tbsp cocoa powder

For the buttercream:

250g salted butter, softened

200g icing sugar, sifted

50g cocoa powder

Dark chocolate, to decorate

Equipment:

2 x 20cm cake tins, greased and lined with baking parchment

Method

1. Preheat the oven to gas mark 3/170C
2. Cream together the butter and sugar until well combined. 
3. In a separate bowl, mix together the eggs then start to incorporate this into the butter/sugar mixture (do this in 3-4 stages, mixing fully after each, to ensure the mixture doesn't split).
4. Measure the flour into a bowl, then replace two tablespoons of flour with the cocoa powder. Sift the flour, again in four stages, into the mixing bowl and fold into the wet mixture with a metal spoon. Once all the flour has been added, mix with the electric whisk for a few minutes to ensure everything is fully combined, and that the mixture is nice and light.
5. Separate into the two tins, and cook on the middle shelf of the oven for 25-30 minutes, until the sponge is springy (fully bounces back if you press on it with a finger) or a skewer inserted into the centre of the cake comes out clean.
6. While the cakes are baking in the oven, make the buttercream. Combine the butter, icing sugar and cocoa powder and whisk until fully mixed. Whisking for a few minutes more gives a really light, fluffy texture.
7. Once the cakes are cooled, place one top side down onto a cake board or pretty plate. Spoon some of the buttercream onto the top and, using a palette knife, work the buttercream around the cake until it is evenly covered. Place the second cake on top, right side up this time, and add the rest of the buttercream to the top and sides. Decorate with chocolate curls (create by scraping a knife over the flat side of a bar of dark chocolate) or anything else you like.