Mocha marble cake with amaretto butter icing

Last night's meeting of the Birmingham Clandestine Cake Club saw my mocha marble cake introduced to the world. It was based on a recipe in this year's Great British Bake Off book, with the addition of an amaretto buttercream topping to fit the meeting's theme of "it's 5 o'clock somewhere".

The ingredients for the cake give nice round weights of 300g for the sponge ingredients, but as with most rich sponge cakes, you should weigh your eggs, then use the same weight of butter, sugar and flour.

For the cake:
300g self raising flour
300g butter, softened - I actually used a 50:50 mix of butter and Stork
300g caster sugar
5 eggs, beaten
35g cocoa
4tsp instant coffee dissolved in 4tsp warm water (cooled before mixing into the cake)
2tbsp milk
1tsp vanilla extract

For the icing:
115g unsalted butter
500g icing sugar
60ml milk
1tsp vanilla extract
1/4tsp amaretto liqueur - I used considerably more than this!

To make the basic cake batter, cream the butter until pale, then beat in the sugar until pale. Gradually add the beaten egg a couple of tablespoons at a time, making sure it's completely incorporated before adding more. Add vanilla extract, then fold in the flour.

Divide the batter evenly into two bowls. To one, add your coffee and gently (but thoroughly) mix it in. To the other, add the cocoa powder and milk, then stir in until no streaks of cocoa can be seen.

Place random 'dollops' from each bowl into your prepared cake tin (I think it was an 8 or 9 inch deep spring form tin - two sandwich thins would also work), gradually filling the tin with a combination of the two flavours. When you've finished, take a knife or skewer and draw it a pattern through the batter. This drags the blobs of each mix into each other to create the marble effect. I went for a figure-of-8 pattern working my way across the tin, and it seemed to work.

Bake at 170-180 degrees for 50-80 minutes, or until the cake starts to pull away from the edges of the tin and a knife inserted into the middle of the cake comes out clean.

Remove from the tin after about 10 minutes and leave on a wire rack to cool completely before icing.

To make the buttercream, simply beat all the ingredients except the amaretto together, then add the amaretto to taste. If the icing becomes too runny, you should be able to stiffen it up by adding additional icing sugar.

If you baked your cake in a single tin, slice it in half across the middle so that you can fill it. Spread around 1/3 of the icing across the bottom half and sandwich the cakes together. Take half of the remaining buttercream, and spread a thin layer across the outside of the cake. This is the 'crumb coat'. Place the cake in the fridge for around 15 minutes for the icing to firm up.

Remove the cake from the fridge and spread on the remaining icing. As a finishing touch, I grated some dark baking chocolate on top of the cake.

Happy baking! There are bread posts to come - I've started a sourdough culture, and been having fun with soda bread and new flours...

All the best,
Bob