Anna Louise Coffee and walnut cake is one of the great British baking combinations — the bitterness of the coffee, the slight earthiness of the walnut, and the sweetness of a light sponge and coffee buttercream all work together in a way that has made this one of the most consistently requested cakes at every bake sale, every coffee morning, and every afternoon tea I have ever attended.
The traybake format makes it practical for a crowd. The same sponge, the same coffee buttercream, the same walnut decoration — but cut into twenty squares rather than twelve slices from a round cake.
No layering, no levelling, no anxiety about whether the icing is even on the sides. Just a beautifully light, coffee-scented sponge topped generously with buttercream and finished with walnut halves.
The coffee flavour here comes from instant espresso dissolved in boiling water — strong, clean coffee flavour that permeates both the sponge and the buttercream without any bitterness.
Use good quality instant espresso rather than regular instant coffee granules — the difference in flavour quality is significant.
Ingredients for Mary Berry Coffee and Walnut Traybake
For the Coffee and Walnut Sponge
- 300g unsalted butter, softened
- 300g golden caster sugar
- 5 large eggs, at room temperature
- 300g self-raising flour, sifted
- 2½ tsp baking powder
- 3 tbsp whole milk
- 3 tsp instant espresso powder dissolved in 2 tbsp boiling water — cooled to room temperature
- 100g walnuts, roughly chopped
For the Coffee Buttercream
- 200g unsalted butter, softened
- 400g icing sugar, sifted twice
- 2 tsp instant espresso powder dissolved in 2 tbsp boiling water — cooled completely
- 1–2 tbsp whole milk if needed
- Pinch of fine salt
To Decorate
- 20–24 walnut halves — one per square
- A dusting of icing sugar (optional)
How to Make Mary Berry Coffee and Walnut Traybake
Step 1 — Preheat and Prepare
Preheat your oven to 180°C / 160°C fan / Gas 4. Grease a 33x23cm traybake tin and line with baking parchment, leaving overhang at both long sides.
Dissolve the espresso powder in the boiling water and leave to cool completely. Both the sponge and the buttercream need cooled coffee — hot coffee in either will cause problems.
Step 2 — Make the Sponge Batter
Beat the softened butter and golden caster sugar together for four to five minutes until pale and very fluffy. Add the eggs one at a time, beating well after each addition.
Sift the flour and baking powder directly into the bowl. Add the milk and the cooled coffee liquid. Fold gently until just combined — stop at the last streak of flour. Add the roughly chopped walnuts and fold through with two or three gentle folds.
Step 3 — Bake
Pour the batter into the prepared tin. Spread evenly to the corners with a palette knife.
Bake for 30 to 35 minutes until deep golden, springy when pressed lightly in the centre, and a skewer inserted into the very centre comes out clean.
Leave to cool completely in the tin — at least one hour — before frosting. Warm sponge melts buttercream immediately.
Step 4 — Make the Coffee Buttercream
Beat the softened butter alone on medium-high speed for four full minutes until very pale and genuinely fluffy. Add the double-sifted icing sugar in three batches, beating well after each. Add the completely cooled coffee liquid, the pinch of salt, and enough milk to bring the buttercream to a smooth, spreadable consistency. Beat for two more minutes until smooth and light.
Taste — the coffee flavour should be clearly present and the buttercream well-balanced between sweet and slightly bitter. Add a few more drops of cooled strong coffee if the flavour seems mild.
Step 5 — Frost and Decorate
Lift the completely cooled sponge from the tin using the parchment overhang. Place on a board.
Spread the coffee buttercream generously and evenly over the entire surface using a palette knife — go right to the edges.
Place one walnut half per portion in a grid pattern across the surface — this marks where to cut and ensures every square has a walnut decoration. A grid of four across and five down gives twenty squares.
Step 6 — Cut and Serve
Cut along the walnut grid lines with a sharp knife. Each square gets one walnut half on top.
My Top Tips For Perfect Coffee and Walnut Traybake
Use instant espresso powder not regular instant coffee. Espresso powder gives a clean, intense coffee flavour without any dusty, slightly artificial note that some regular instant coffees can have. The difference is worth the minor additional cost.
Cool the coffee liquid completely before using in both the sponge and the buttercream. Warm coffee in the buttercream melts the butter and gives a runny, difficult-to-spread result. In the sponge, warm liquid can begin to activate the baking powder before the batter goes into the oven. Always cool completely.
Beat butter alone for four minutes. Consistent advice across every buttercream recipe on this site — because it is consistently the most important step. Four minutes of beating butter alone creates the light, aerated base that gives silky, pipeable buttercream. Three minutes is not enough.
Walnuts in a grid pattern for decoration. One walnut half per square, arranged in rows, serves two purposes — it looks beautiful and it tells you exactly where to cut. Every square gets the same amount of decoration.
Be generous with the buttercream. A traybake with a thin scraping of frosting looks mean. Use all the buttercream and spread it thickly and evenly — the buttercream is half the appeal of a coffee and walnut traybake.
Serving Suggestions
At a coffee morning — this is its natural home. At a bake sale — coffee and walnut is one of the most reliably popular flavours. As an afternoon tea traybake. As a celebration bake for anyone who considers coffee and walnut their favourite cake.
How to Store
At room temperature: Store in an airtight container for up to 4 days. The sponge stays moist and the buttercream holds its shape.
In the freezer: Freeze unfrosted squares individually for up to 3 months. Add buttercream fresh after defrosting.
Mary Berry Coffee and Walnut Traybake Recipe
Ingredients
Method
- Preheat oven to 180°C / 160°C fan / Gas 4. Grease and line a 33x23cm tin. Dissolve espresso in boiling water — cool completely.
- Beat butter and sugar 4–5 minutes until pale and fluffy. Add eggs one at a time. Sift in flour and baking powder. Add milk and cooled coffee. Fold gently until just combined. Fold in walnuts.
- Pour into tin — spread evenly. Bake 30–35 minutes until golden and skewer comes out clean. Cool completely in tin — at least 1 hour.
- Beat butter alone 4 minutes. Add icing sugar in 3 batches. Add cooled coffee, salt, and milk if needed — beat 2 more minutes until smooth and light.
- Lift sponge from tin. Spread buttercream generously over entire surface. Place walnut halves in a grid — one per portion. Cut along the grid lines.
Notes
Frequently Asked Questions
Can I leave out the walnuts from the sponge?
Yes — the coffee sponge is equally good without walnuts inside. Keep the walnut halves for decoration only if preferred.
Can I use brewed espresso instead of dissolved espresso powder?
Yes — use two tablespoons of very strong brewed espresso in the sponge and two tablespoons in the buttercream. Make sure it is completely cool before using in both.
Can I make this as a round layer cake?
Yes — divide the batter between two deep 20cm round sandwich tins. Bake for 26 to 30 minutes. Fill and top with the buttercream and decorate with walnut halves.
Why is my coffee buttercream too dark?
Too much espresso powder or the coffee liquid was too concentrated. Use the stated quantities — the buttercream should be a warm beige colour, not dark brown.
Can I use pecans instead of walnuts?
Yes — pecans give a slightly sweeter, less bitter result. The flavour combination with coffee is excellent.
Leave a Reply