Coffee and Walnut Cake Recipe: Real Coffee in Every Layer
- How Do You Make a Coffee and Walnut Cake?
- What Do You Need for a Coffee and Walnut Sponge?
- How Do You Get Real Coffee Flavour Into the Sponge?
- How Do You Make the Sponge, Step by Step?
- How Do You Stop the Walnuts From Sinking?
- What Is the Right Consistency for Coffee Buttercream?
- How Do You Assemble the Cake?
- Who Should You Tell About the Walnuts?
- What Do You Serve With Coffee and Walnut Cake?
- Sources
How Do You Make a Coffee and Walnut Cake?
A coffee and walnut cake is a Victoria-style sponge with two changes: strong dissolved coffee goes into the batter, and chopped walnuts are folded in at the end. Weigh four eggs, match that weight in butter, sugar and self-raising flour, cream, add the eggs and coffee, fold in the flour and 75g chopped walnuts, then bake in two 20cm tins at 180C (160C fan / 350F) for 20 to 25 minutes. Sandwich and top with coffee buttercream and walnut halves.
If you have made our equal-weights Victoria sponge, you know most of this cake. The rest is making the coffee taste of coffee, getting the buttercream right, and keeping the walnuts out of a layer at the bottom.
What Do You Need for a Coffee and Walnut Sponge?
This makes a two-layer 20cm (8 inch) cake that serves 8 to 10.
For the sponge
| Ingredient | Quantity | Notes |
|---|---|---|
| Eggs | 4 medium, weighed in their shells (roughly 220 to 240g) | Room temperature |
| Butter | Same weight as the eggs | Softened |
| Sugar | Same weight as the eggs | Caster, or light soft brown for a deeper flavour |
| Self-raising flour | Same weight as the eggs | No extra baking powder needed |
| Instant coffee granules | 2 teaspoons | Dissolved in 2 tablespoons of just-boiled water, then cooled |
| Walnuts | 75g | Chopped to roughly pea size |
For the coffee buttercream
| Ingredient | Quantity | Notes |
|---|---|---|
| Butter | 150g | Properly soft |
| Icing sugar | 300g | Sifted |
| Instant coffee granules | 2 teaspoons | Dissolved in 1 tablespoon of just-boiled water, then cooled |
| Milk | 1 to 2 teaspoons | Only if needed to loosen |
| Walnut halves | 8 to 10 | For the top |
The coffee quantity in the sponge is not our invention. Mary Berry's coffee and walnut traybake, reprinted by HELLO! magazine, calls for coffee essence and notes that instant coffee can be used instead: 2 teaspoons of granules mixed with 2 tablespoons of water. The same recipe uses 75g of chopped walnuts in a four-egg batter, which is the quantity we follow here.
How Do You Get Real Coffee Flavour Into the Sponge?
Butter and sugar muffle coffee. A splash of brewed coffee from the pot gives sweet sponge with a faint suggestion of something brown. The fix is concentration: a lot of coffee in very little liquid, which is why the recipe uses dissolved instant granules. Two tablespoons of liquid is about what a Victoria sponge batter can take before it goes too loose, and in our base method that is the same job the optional 1 to 2 tablespoons of milk would do. So the coffee replaces the milk; it does not add to it.
A few practical points:
- Cool the coffee before it goes in. Use just-boiled water to dissolve the granules, then let the mixture stand until it reaches room temperature. Warm liquid softens the creamed butter and can make the batter split.
- Bottled coffee essence works too. It is a ready-made concentrated liquid coffee flavouring. Mary Berry's traybake uses 2 tablespoons of it in the sponge, the same volume as the dissolved granules here.
- Adjust strength in the icing, not the sponge. Extra liquid would loosen the batter; the buttercream is where a little more coffee can go.
How Do You Make the Sponge, Step by Step?
- Prepare. Heat the oven to 180C (160C fan / 350F / Gas 4). Butter two 20cm sandwich tins and line the bases with baking parchment. Dissolve the sponge coffee and leave it to cool.
- Cream. Beat the butter and sugar for 3 to 5 minutes with an electric mixer until pale and fluffy. With light soft brown sugar the mixture never goes as pale as it does with caster, so judge by the fluffy texture instead.
- Add the eggs. Beat the eggs in a jug and add them a little at a time, beating well after each addition. If the mixture starts to curdle, add a spoonful of the weighed flour.
- Add the coffee. Beat in the cooled coffee in two or three splashes.
- Fold. Sift in the flour and fold gently until no dry streaks remain. Fold the chopped walnuts in with the last few turns.
- Bake. Divide the batter evenly between the tins, level it, and bake for 20 to 25 minutes without opening the door for the first 20. The sponges are done when they spring back when pressed in the centre, are just shrinking from the sides of the tins, and a skewer pushed into the middle comes out clean.
- Cool. Use oven gloves to take out the tins. Leave the sponges in the tins for 5 to 10 minutes, then turn them out onto a wire rack and cool completely before icing.
How Do You Stop the Walnuts From Sinking?
Walnuts are denser than the batter around them, so a loose batter lets them drift down as the cake rises. The equal-weights sponge has enough body to hold them, as long as you do not loosen it. What actually helps:
- Do not add extra liquid. The 2 tablespoons of coffee are the liquid. Skip the milk. The batter should drop reluctantly off a spoon, not pour.
- Chop the walnuts smaller. Pea-sized pieces sit in the crumb far more evenly than halves or large chunks, which are heavy enough to drop through even a good batter.
- Fold them in last, and briefly. Every extra turn of the spatula knocks out air and thins the batter.
What does not reliably help is the old trick of tossing the nuts in flour first. Writing about berries and chocolate chips, Milk Street says plainly that "tossing inclusions in flour never works", arguing that what matters most is a batter with enough strength and structure to hold inclusions in place. Get the batter consistency right and the coating has nothing left to do.
For a toastier flavour, toast the walnuts in a dry frying pan over a low heat for a few minutes, stirring, until they smell nutty. Take them off the heat as soon as they colour and cool them completely before folding in; warm nuts melt the butter in the batter.
What Is the Right Consistency for Coffee Buttercream?
Coffee buttercream is plain buttercream with dissolved coffee beaten in. Beat the soft butter for a minute or two until creamy, add the sifted icing sugar in two or three batches, then beat in the cooled coffee and keep beating for another 2 to 3 minutes until it is light and smooth.
Our recipe uses two parts icing sugar to one part butter by weight, which gives a soft, buttery icing that spreads easily over a tender sponge. Mary Berry's versions run firmer: her traybake topping uses 75g butter to 225g icing sugar, and her mini coffee and walnut cakes on PBS use 150g butter to 450g icing sugar, both three parts sugar to one part butter. If your kitchen is warm or the cake has to travel, the firmer ratio is worth using.
The consistency test is simple. For filling, the buttercream should hold a soft peak on the back of a spoon and spread without dragging crumbs off the sponge. For the top, it can be a touch firmer so the swirls and walnut halves hold their place. If it is too stiff, beat in milk a teaspoon at a time. If it is too soft and sliding, chill the bowl for 10 to 15 minutes and beat again.
How Do You Assemble the Cake?
Put one sponge top-side down on the plate and spread half the buttercream over it, right to the edges. Set the second sponge on top, flat base upwards for a level surface, spread over the rest, and finish with walnut halves around the edge so each slice gets one.
A buttercream-filled cake keeps in an airtight tin at room temperature for a couple of days, the same as a buttercream-filled Victoria sponge.
Who Should You Tell About the Walnuts?
Walnuts are named under tree nuts in the UK government's list of 14 allergens that businesses must tell customers about. If you are serving this cake to guests, tell everyone it contains walnuts before it is cut, and keep it apart from any nut-free bakes on the table.
What Do You Serve With Coffee and Walnut Cake?
It sits well alongside lighter bakes on a tea table; our guide to afternoon tea bakes covers how to balance a spread. As for the pot, a robust black tea stands up to coffee buttercream better than a delicate one, and our guide to brewing tea properly gives the water temperatures and steeping times by type.