Squidgy, dark and rich, this cake makes a showstopping birthday cake. It’s perfect for dessert too. As with most bakes, this cake is best eaten the day it’s made, but the sponges can be made up to two days ahead and kept in an airtight container if needed.
Preparation time: 30 minutes, plus cooling time
Cooking time: 35 minutes
Cuts into 12 slices
225g unsalted butter, plus extra for greasing
300g dark chocolate, 70 per cent cocoa
300g golden caster sugar
4 medium eggs
150ml buttermilk or mild natural yoghurt
1 teaspoon vanilla extract
150g self-raising flour
1/2 teaspoon flaky sea salt
1/2 teaspoon baking powder
25g cocoa powder
50g icing sugar
150ml sour cream or double cream
Rub a little butter around the insides of two loose-bottomed 20cm cake tins, then line the bases with circles of baking parchment. Preheat the oven to 160 degrees.
Break the chocolate into squares and put 200g of it into a heatproof bowl. Put the bowl over a pan of simmering water, make sure that the bowl doesn’t touch the water, then leave the chocolate to melt for about five minutes, stirring once or twice, until smooth and even. Alternatively, microwave on high for one minute.
Put 200g of the butter into a large bowl, then add the caster sugar, eggs, buttermilk or yoghurt, vanilla, flour, salt and baking powder. Sift in the cocoa powder.
Using hand-held electric beaters or a stand mixer, beat everything together until smooth and creamy. Don’t worry if you have any lumps of butter – they’ll melt when the warm chocolate goes in next.
Pour in the melted chocolate and beat again briefly until the mixture is even and smooth.
Divide the batter equally between the prepared tins. Keep the chocolatey bowl – you’ll need it to make the frosting later.
Bake the cakes, both on the same shelf, for 35 minutes, or until risen in the middle, and a skewer inserted into the middle of the cake comes out clean. Cool the cakes in their tins for 10 minutes, then turn them out onto a wire cooling rack to cool completely. The tops of the cakes are quite delicate, so take care as you do this.
While the cakes cool, make the icing. Put the rest of the chocolate and butter into the chocolatey bowl and melt together over a pan of simmering water, as in step 2.
Take the bowl from the heat, sift in the icing sugar and pour in the cream. Stir to a smooth liquid mixture. It will thicken up to a spreading consistency as it cools. Do not chill it.
Use a palette knife to spread half of the chocolate icing over one of the sponges.
Transfer to a serving plate. Top with the second cake, then spread the rest of the icing over the top. Cut into slices to serve.
What To Cook & How To Cook It.