Coffee and walnut cake (10 inch square)

I like my coffee cake to have a bit of cocoa in – more of a mocha cake – but also can’t resist walnuts if I can find them.  Using real espresso if you are passing a coffee shop would probably make this even better, but I find that instant coffee mixed with the smallest amount of boiling water you can get away with to create a smooth syrupy mixture works just as well.  There’s also Camp coffee essence (I found it in Asda but nowhere else) which works really well – it’s especially good for the icing and creates a fantastically rich, golden colour when mixed with mascarpone and icing sugar.

I recently made four batches of this recipe to make sixty four 2½ inch square coffee cakes for my friend Emily’s wedding.  I used a 10 inch square cake tin and did quite a lot of experimenting to get the quantities right – it needed to be deep enough to only need one layer of cake, and not sink in the middle.  I found the trick for this was to scoop all the mixture away from the centre of the cake tin (so you’ve got a square ‘doughnut’), and as it bakes it evens itself out so it comes out completely level... trust me! 

For a smaller cake in a 24cm tin, use three eggs and halve all the other ingredients.

Ingredients

8oz butter, softened

4oz margarine

12oz caster sugar

5 eggs

2 tbsp coffee essence/ espresso

12oz self-raising flour

2 oz cocoa powder

1 tsp baking powder

8oz walnuts, chopped

For the icing

50g butter

250g icing sugar

75g mascarpone

75ml Camp coffee essence

Method

1. Pre-heat the oven to 180°C and grease and line a 10inch square tin.
2. In a very large mixing bowl, cream the butter, margarine and sugar until pale and fluffy.
3. In a separate bowl, use an ordinary whisk to beat the eggs one at a time, mixing them into the butter mixture with a spoonful of the flour between each egg (to stop it curdling). 
4. Beat in the coffee essence.
5. Sift the remaining flour together with the cocoa and baking powder and fold in with a metal spoon.
6. Fold in the walnuts.
7. Pour the mixture into the tin (leaving a hole in the middle) and bake for an hour or until a cake tester comes out clean.
8. Allow to cool completely on a wire rack before icing.
9. To make the icing, use a wooden spoon to beat the butter and sifted icing sugar until smooth.  Beat in the mascarpone and then the coffee essence.  Cover and transfer to the fridge until the cake is cool enough to ice.  Decorate with walnut pieces or chocolate-coated coffee beans.