This classic coffee and walnut traybake cake is a timeless British bake that brings together a soft coffee-infused sponge, nutty walnuts, and a smooth coffee buttercream topping. Baked in a tray and cut into neat squares, it’s perfect for sharing at family gatherings, afternoon tea, or casual celebrations. Simple, comforting, and full of flavor, this is the kind of cake that never goes out of style.
Why You’ll Love This Recipe
This traybake version of coffee and walnut cake is easy to prepare and even easier to serve. There’s no layering or complicated decoration involved, yet the result feels special and indulgent. The coffee flavor is rich without being overpowering, the walnuts add a gentle crunch, and the buttercream ties everything together beautifully. It’s a reliable, crowd-pleasing bake that works just as well for everyday treats as it does for special occasions.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
For the sponge:
200 g unsalted butter, softened
200 g light brown sugar
4 large eggs, at room temperature
200 g self-raising flour
2 tablespoons instant coffee granules dissolved in 2 tablespoons hot water
100 g walnuts, roughly chopped
For the buttercream:
150 g unsalted butter, softened
300 g icing sugar, sifted
2 tablespoons instant coffee granules dissolved in 1 tablespoon hot water
For topping:
Walnut halves, as needed
Directions
Preheat the oven to 180°C (350°F). Grease and line a 9×13-inch traybake tin with baking paper.
In a large mixing bowl, cream the softened butter and light brown sugar together until pale and fluffy. This step helps create a light, tender sponge.
Beat in the eggs one at a time, mixing well after each addition. If the mixture starts to curdle, add a tablespoon of the flour to bring it back together.
Gently fold in the self-raising flour, followed by the dissolved coffee and chopped walnuts, until the batter is smooth and evenly mixed.
Pour the batter into the prepared tin and level the surface. Bake for 25 to 30 minutes, or until a skewer inserted into the center comes out clean. Allow the cake to cool completely in the tin, then transfer to a cooling rack.
To make the buttercream, beat the butter until creamy. Gradually add the icing sugar, mixing well, then beat in the dissolved coffee until smooth and spreadable.
Spread the buttercream evenly over the cooled sponge. Finish by decorating with walnut halves, then cut into squares to serve.
Servings and timing
This recipe makes approximately 16 generous squares.
Preparation time is about 20 minutes, with a baking time of 25 to 30 minutes. Allow additional time for cooling before icing and slicing.
Variations
You can swap the walnuts for pecans or hazelnuts if preferred. For a lighter topping, replace half of the buttercream with mascarpone. Decaffeinated instant coffee can be used for a milder coffee flavor without the caffeine. A small splash of vanilla extract in the sponge also works well for added warmth.
Storage/Reheating
Store the traybake in an airtight container at room temperature for up to 3 days. If the weather is warm, keep it refrigerated and allow it to come to room temperature before serving. The sponge freezes well without the buttercream for up to 2 months; thaw fully before icing.
FAQs
Can I make this cake ahead of time?
Yes, the sponge can be baked a day in advance and iced the next day for convenience.
Can I use plain flour instead of self-raising flour?
Yes, add 2 teaspoons of baking powder to plain flour to achieve a similar rise.
Is instant coffee necessary?
Instant coffee provides a strong, clear coffee flavor, but finely brewed coffee can be used if reduced slightly.
How do I prevent the cake from drying out?
Avoid overbaking and store the cake in an airtight container once cooled.
Can I reduce the sweetness of the buttercream?
You can replace part of the icing sugar with mascarpone or cream cheese for a less sweet topping.
Can I make this recipe gluten-free?
A good quality gluten-free self-raising flour blend works well in this recipe.
What size tin works best?
A 9×13-inch traybake tin gives even thickness and neat slices.
Can I add more walnuts?
Yes, you can increase the walnuts slightly if you prefer extra crunch.
Why did my sponge sink?
This usually happens if the oven door is opened too early or the batter is overmixed.
Can this be made as a layered cake?
Yes, the batter can be divided between two round tins and baked as a traditional layer cake.
Conclusion
This classic coffee and walnut traybake cake is a dependable, comforting bake that delivers on flavor and nostalgia. With its soft coffee sponge, creamy buttercream, and crunchy walnut topping, it’s the kind of recipe you’ll return to again and again. Whether you’re baking for guests or simply treating yourself, this traybake is always a satisfying choice.
This classic coffee and walnut traybake cake features a soft, coffee-flavored sponge with chopped walnuts and a smooth coffee buttercream topping. It’s baked in a tray and sliced into squares, making it perfect for sharing, afternoon tea, or casual celebrations.
Ingredients
For the sponge:
200 g unsalted butter, softened
200 g light brown sugar
4 large eggs, room temperature
200 g self-raising flour
2 tbsp instant coffee granules dissolved in 2 tbsp hot water
100 g walnuts, roughly chopped
For the buttercream:
150 g unsalted butter, softened
300 g icing sugar, sifted
2 tbsp instant coffee granules dissolved in 1 tbsp hot water
For topping:
Walnut halves, as needed
Instructions
Preheat oven to 180°C (350°F). Grease and line a 9×13-inch traybake tin with parchment paper.
Cream butter and sugar until light and fluffy.
Beat in eggs one at a time, mixing well after each. Add a little flour if the mixture curdles.
Fold in self-raising flour, dissolved coffee, and chopped walnuts until smooth.
Spread the batter evenly in the tin and bake for 25–30 minutes, or until a skewer comes out clean. Cool completely.
For the buttercream, beat softened butter until creamy. Gradually add icing sugar, then beat in dissolved coffee until smooth.
Spread buttercream over the cooled cake. Decorate with walnut halves and cut into squares to serve.
Notes
Use pecans or hazelnuts instead of walnuts for variety.
Add a splash of vanilla extract to the batter for extra depth.
Replace some buttercream with mascarpone for a lighter topping.
Use decaf coffee for a caffeine-free version.
The sponge freezes well without buttercream—ice after thawing.
