With St. Patrick’s Day just around the corner, this classic Irish farmhouse-style coffee-and-walnut sponge cake makes a wonderfully fitting teatime treat. With its rich coffee flavour, crunchy walnuts and light, fluffy sponge, it is the perfect cake to enjoy before heading off to join the celebrations.
Better still, it can be made in under an hour. The sponge is packed with crunchy walnuts and infused with the irresistible aroma of coffee, while the smooth icing adds a creamy, tiramisu-like touch that contrasts beautifully with the nutty cake.
Icing flavour options
If you’d like to give this cake a boozy twist, I recommend adding coffee liqueur, such as Kahlúa, only to the icing.
For a more distinctly Irish flavour, you can swap the Kahlúa for Baileys Irish Cream in the icing instead.
One layer or two?
This recipe is written for a simple one-layer iced coffee and walnut cake. For a taller, more indulgent version, double the recipe and bake the batter in two round cake tins instead of one.
Double the buttercream icing as well, then spread some over the first cake layer, sandwich with the second cake, and finish icing the top as directed.
Decorating the cake
This cake does not require any special icing skills to decorate. Simply spread the icing over the top with a metal spatula, leaving visible ridges for a rustic look.
Transfer a little icing to a piping bag fitted with your favourite nozzle, then pipe swirls evenly around the edge of the cake, adding a few extra in the centre if desired. Finish by placing a walnut half between every second swirl and a chocolate-coated coffee bean between the others.
GOOD TO KNOW!
Despite the name, it is quite different from American coffee cake. In the British and Irish style, the cake is actually flavoured with coffee, whereas American coffee cake is usually a cinnamon-style cake served alongside coffee.
Gluten-Free Coffee & Walnut Cake
Equipment
- Stand mixer or
- Round cake tin (24 cm)
Ingredients
Cake
- 150 g unsalted butter, plus extra to grease the tin
- 120 g light brown sugar
- 3 medium eggs, lightly beaten
- 150 g store-bought or homemade gluten-free plain flour
- ½ tsp xanthan gum
- 1½ tsp gluten-free baking powder
- ¼ tsp salt
- 55 g walnuts, chopped finely
- 4 tbsp cold espresso coffee (regular or decaf)
Coffee Buttercream Icing
- 150 g unsalted butter, at room temperature
- 300 g icing (confectioner’s) sugar, sieved
- 2 tbsp cold espresso coffee (or Kahlúa or Bailey’s Irish Cream)
Cake Decorations
- 12 walnut halves
- 12 chocolate-coated coffee beans (optional)
Instructions
Cake
- Grease a 24 cm round cake tin with some butter. Sprinkle with flour, tip out the excess, then line the base with a fitted sheet of baking paper.
- In a medium bowl, whisk the flour with the xanthan gum, baking powder and salt to combine. Set it aside.
- Finely chop the walnuts. Set them aside.
- Either use a stand mixer or a handheld electric mixer to beat the butter and sugar until pale and fluffy.
- One by one, add the eggs to the butter mixture, mixing well.
- Using a large spatula, gradually fold in the flour mixture with the cold coffee. Stop folding when no flour streaks are visible.
- Once combined, fold in the finely chopped walnuts.
- Spread the cake batter into the prepared cake tin.
- Bake for 25-30 minutes at 140°C fan-assisted(160°C/325°F), or until the cake appears golden, and test for doneness by inserting a toothpick into the centre of the cake. If it comes out clean, the cake can be removed from the oven.
- Leave the tin to cool for at least 10 minutes before turning it out onto a wire rack to cool further.
- Peel off the lined baking paper from the cake and transfer it to a serving plate to start icing. The icing will be spread on the lined baking paper side as it will be perfectly flat.
Coffee Buttercream Icing
- Either use a stand mixer or a handheld electric mixer, cream the butter until light and fluffy.
- Whisk in the Kahlúa (or coffee) into the creamed butter.
- Add the sieved icing sugar gradually to the creamed butter until soft peaks form.
- During warm weather, chill the buttercream icing for 30 minutes before decorating the cake.
Decorating
- Dollop the icing onto the cake, leaving a small amount aside.
- Spread it with a metal spatula, leaving soft ridges for a rustic finish.
- Spoon the small amount of icing into a piping bag fitted with your favourite nozzle, then pipe swirls evenly around the edge of the cake, adding a few in the centre if you like.
- Place a walnut half between every second swirl, then add a chocolate-coated coffee bean in each of the remaining spaces.
Serving
- Serve immediately at room temperature or chill to serve later. If possible, place the cake in a large, lidded container for overnight storage. This prevents the icing from discolouring and forming a crust.
Notes
- Keeps chilled for 3 days.
- Suitable for freezing sliced into portions.
