Ingredients:

• 175 g butter (at room temperature) , plus extra for greasing
• 75 g walnuts , plus extra to garnish
• 175 g sugar
• 3 large free-range eggs
• 150 g self-raising flour
• ½ teaspoon baking powder
• 50 ml cold espresso

Coffee Filling

• 65 g unsalted butter
• 125 g icing sugar
• 40 ml strong espresso

Coffee Icing

• 100 g icing sugar
• 20 ml strong espresso

Procedure

1. Preheat the oven to 180ºC/gas 4. Grease and line the bases of 2 round 20cm cake tins.
2. In a food processor, blend two-thirds of the nuts to powder. Cream the butter in a bowl with the sugar until light and fluffy. Gradually beat in the eggs then add the blended  walnuts and gently stir through.
3. Fold the flour, baking powder and a pinch of sea salt through with a large metal spoon until just mixed
4. Roughly chop the rest of the walnuts and stir through the cake mixture along with the espresso.
5. Evenly divide the mixture between the cake tins and bake in the oven for 20 to 25 minutes, or until lightly golden and cooked through when tested with a skewer.
6. Cool the cakes in the tins for 5 minutes, then transfer to a wire rack to cool.
7. For the filling, soften butter in a bowl. Sift in the icing sugar, beat until fluffy, then beat in the coffee.
8. For the icing, sift the icing sugar into a bowl and beat in the coffee to make a thick, smooth icing.
9. Place one of the cakes on a plate or board and spread with the coffee filling. Top with the second cake and drizzle over the icing.
10. Decorate the cake with the remaining walnuts