Coffee Walnut Cake

Ingredients

For the sponges

• 340g unsalted butter, plus extra for greasing
• 340g caster sugar
• 250g plain flour
• 90g walnuts
• 3 tsp baking powder
• 6 large eggs
• 3 tsp instant coffee dissolved in 1.5 tbsp boiling water

For the frosting / topping

• 750g icing sugar
• 250g unsalted butter
• 4 tsp instant coffee dissolved in 2 tbsp boiling water
• 2 tbsp milk
• approx 9 walnut halves for decorating

Equipment needed

• 3 - round sandwich tins (20cm)
• Baking parchment
• Stand mixer or electric hand whisk
• Food processor
• Offset palette knife
• Silicone spatula
• Sieve
• Kitchen scales
• 2 x wire cooling racks
• Display plate or cake board

Recipe

1. Preheat the oven to 180oC / 160oC Fan / Gas Mark 4 (I have a fan oven so all my recipes are tested at the fan temperatures). To make the sponges, grease and line three 20cm sandwich tins with baking parchment. If you only have one or two tins, you can still do the cake, but you’ll have to do the baking in batches
2. Weigh out the walnut halves and dry fry in a frying pan over a medium heat for 5 minutes, or until the oils start to release the walnut aroma. Set aside to cool while you prepare the rest of the sponge mixture
3. Beat together the sugar and butter with an electric hand whisk, or a stand mixer if you have one, until they are light coloured, smooth and creamy. Beat in each egg thoroughly, one by one (rather than dropping them all in together). If the mixture starts to split, just add a tablespoon of flour and continue beating – this will bring the mixture back
4. Dissolve the coffee in the boiling water and fold this into the wet mix
5. Weigh and measure the flour and the baking powder and put into a food processor. Add the cooled walnuts. Blitz thoroughly until all the nuts are incorporated and form a light, fine powder
6. (If you don’t have a food processor, you can try crushing the walnuts as small as possible by putting them in a sandwich bag and whacking them with a rolling pin but it will be difficult to get them fine enough to work in the cake)
7. Fold the dry ingredients into the wet mixture using a silicone spatula, making sure to mix any flour that ends up at the bottom of the bowl. Be gentle when you’re folding in the flour – you don’t want to knock out any air you’ve incorporated into the mix through all that whisking!
8. Divide the mixture evenly between the three tins. Smooth out the surface of the sponge mixtures with an offset palette knife and bake for about 23-28 minutes (keep an eye on it from 20 minutes), or until a cocktail stick comes out clean when poked into the centre of the sponge
9. Remove from the oven and when the tins have cooled enough to handle, take the sponges out of the tins and set to cool on wire racks
10. While the sponges are cooling, prepare the coffee butter cream icing. Weigh the butter into a bowl and beat with an electric hand whisk until soft. Gradually add the icing sugar and continue to mix. Make up the coffee and beat into the mixture. Add 2 tbsp milk if you need to loosen the butter cream a little more
11. Once the sponges have cooled, if they have raised middles, slice the tops flat with a bread knife (I usually spread a bit of the icing on the off cuts to taste a secret preview of the final cake)
12. Put the bottom sponge on your display plate or cake board. Neatly spread about 1/3 of the butter-cream icing onto the bottom layer of sponge using an offset palette knife. Try to spread evenly, and right up to the edges of the sponge, so you can see a neat line of icing once the top layer of sponge goes on
13. Add the next sponge and repeat. Turn the top layer of sponge upside down and lie on top of the spread icing; pressing down gently, and scraping off any excess icing that squidges out of the middle
14. Using the offset palette knife, neatly spread the remaining icing on the top of the cake and garnish with the remaining walnut halves.