**Instructions**
**For the Cake:**
1. Preheat your oven to 180°C (160°C fan/350°F/Gas Mark 4). Grease and flour two 20cm (8-inch) round cake tins, or line with baking parchment.
2. In a large mixing bowl, cream together the softened butter and caster sugar until light and fluffy.
3. Beat in the eggs one at a time, incorporating each fully before adding the next. If the mixture looks like it’s curdling, add a spoonful of flour.
4. Sift the self-raising flour and baking powder into the wet mixture. Gently fold it in until just combined, being careful not to overmix.
5. Stir in the cooled dissolved coffee and the chopped walnuts until evenly distributed.
6. Divide the batter evenly between the two prepared cake tins.
7. Bake for 20-25 minutes, or until a skewer inserted into the center comes out clean.
8. Remove the cakes from the oven and let them cool in the tins for 10 minutes before turning them out onto a wire rack to cool completely.
**For the Velvety Coffee Icing:**
1. In a clean mixing bowl, beat the softened butter until smooth and pale.
2. Gradually add the sifted icing sugar, beating on a low speed until combined, then increase the speed and beat until light and fluffy.
3. Stir in the cooled dissolved coffee and the milk, one tablespoon at a time, until you achieve a smooth, velvety consistency that’s easy to spread. If it’s too thick, add a tiny bit more milk; if too thin, add a little more sifted icing sugar.
**Assembling the Cake:**
1. Once the cakes are completely cool, place one cake layer on your serving plate or cake stand.
2. Spread about a third of the coffee icing evenly over the top of this layer.
3. Carefully place the second cake layer on top.
4. Use the remaining icing to cover the top and sides of the cake, creating a smooth finish or decorative swirls as desired.
5. Decorate the top with extra walnut halves or chopped walnuts before serving.
**Short Tips**
* **Room Temperature Ingredients:** Ensure your butter and eggs are at room temperature for the best cake texture and easier creaming.
* **Don’t Overmix:** Overmixing the flour can lead to a tough cake. Fold gently until just combined.
* **Cool Completely:** Always allow cakes to cool fully before icing, otherwise, your icing will melt and slide off.
* **Strong Coffee:** For a more pronounced coffee flavor, use a strong instant coffee for both the cake and icing.
* **Icing Consistency:** If your icing is too stiff, add a tiny drop more milk. If it’s too runny, add a little more sifted icing sugar.
