Coffee and walnut cake

This is one of Nigella's recipes and is so delicious! The is a favourite amongst the guys...

Ingredients:

For the sponge:

50 g walnut pieces

225 g caster sugar

225 g soft butter (preferably unsalted)

200 g plain flour

4 tsp instant coffee granules (dissolved in 2 tablespoons boiling water)

2 ½ tsp baking powder

½ tsp bicarbonate of soda

4 large eggs

1 - 2 Tblsp milk

For the icing:

350 g icing sugar

175 g soft unsalted butter

2 ½ tsp instant coffee (dissolved in 1 tablespoon boiling water)

approx. 10 walnut halves (to decorate)

Method:

1. Preheat the oven to 180°C. Grease two 20cm cake tins.

2. Put the walnut pieces and sugar into a food processor and blitz to a fine nutty powder.

3. Add the butter, flour, coffee, baking powder, bicarb and eggs to the sugar mix and process to a smooth batter.

4. Add the milk and continue beating to loosen the cake mixture.

5. Divide the mixture between the 2 cake tins and bake in the oven for 25 minutes or until a skewer comes out clean.

6. To make the icing, mix the butter and icing sugar. Add the coffee and continue mixing until the icing is smooth.

7. Once the cake is cool, place 1 sponge layer on a serving plate and spread with half the icing. Place the second sponge on top and cover the top with the remaining icing. Gently press the walnut halves onto the top of the cake.