Coffee and Walnut Cake

Coffee and walnut cake is my Nanna's favourite cake. It's also in my top three and I'm yet to find even the most stalwart anti-coffee person who doesn't like it in cake form. There's just something wonderful about the kick of espresso, the sweetness of the nuts and the comfort of a perfectly soft sponge.

This recipe belongs to Nigella Lawson - the queen of cake - and the reason I like it so much is the fact that the walnuts are blitzed together with the sugar so that the whole of the cake it perfumed with their delightful nuttiness. If you don't have two cake tins, you can bake the whole lot in one go - bake for 35-40 minutes and cover with tin foil or baking paper for the first 25 minutes.

Coffee and Walnut Cake

For the sponge:

50g walnut pieces 

225g caster sugar 

225g soft unsalted butter (plus some for greasing) 

200g plain flour

4 tsp instant espresso powder 

3 tsp baking powder 

4 large eggs 

1-2 tbsp milk 

For the buttercream frosting:

350g icing sugar 

175g soft unsalted butter 

2½ tsp instant espresso powder (dissolved in 1 tablespoon boiling water) 

walnut pieces, for decoration

Preheat the oven to 180°C/160°C Fan/gas mark 4/350°F. Butter two 20cm / 8inch sandwich tins and line the base of each with baking parchment. 

Put the walnut pieces and sugar into a food processor and blitz to a fine nutty powder. Add the sugar, flour, espresso powder, baking powder and eggs and process to a smooth batter. Add the milk, pouring it down the funnel with the motor still running, or just pulsing, to loosen the cake mixture: it should be a soft, dropping consistency, so add more milk if you need to. (If you are making this by hand, bash the nuts to a rubbly powder with a rolling pin and mix with the dry ingredients; then cream the butter and sugar together, and beat in some dry ingredients and eggs alternately and, finally, the milk.) 

Divide the mixture between the 2 lined tins and bake in the oven for 25 minutes, or until the sponge has risen and feels springy to the touch. Cool the cakes in their tins on a wire rack for about 10 minutes, before turning them out onto the rack and peeling off the baking parchment. 

When the sponges are cool, you can make the buttercream. Pulse the icing sugar in the food processor until it is lump free, then add the butter and process to make a smooth icing. Dissolve the instant espresso powder in the 1 tablespoon boiling water and add it while still hot to the processor, pulsing to blend into the buttercream. If you are doing this by hand, sieve the icing sugar and beat it into the butter with a wooden spoon. Then beat in the hot coffee liquid. 

Place 1 sponge upside down on your cake stand or serving plate. Spread with about half the icing; then place on it the second sponge, right side up (i.e. so the 2 flat sides of the sponges meet in the middle) and cover the top with the remaining icing in a ramshackle swirly pattern. This cake is all about old-fashioned, rustic charm, so don’t worry unduly: however the frosting goes on is fine. similarly, don’t fret about some buttercream oozing out around the middle: that’s what makes it look so inviting. Gently press the walnut pieces into the top.