Step 1

Preheat the oven to 180C/160C Fan/Gas Lightly butter two loose-bottomed 18cm/7in sandwich tins and line the bases with baking paper.

Step 2

Put the butter, sugar, eggs, flour, baking powder, walnuts and coffee essence in a large mixing bowl and beat together (using an electric hand whisk if you have one) until well combined and smooth.

Step 3

Divide the mixture evenly between the tins. Level the surface using a spatula or the back of a spoon.

Step 4

Bake for 20–25 minutes, or until an inserted skewer comes out clean. Leave the cakes to cool in the tins for 5 minutes, then run a small palette knife or rounded butter knife around the edge of the tins and carefully turn the cakes out onto a wire rack. Peel off the paper and leave to cool completely.

Step 5

For the filling and topping, beat the butter and gradually add the icing sugar. Add the milk and coffee essence and beat until smooth.

Step 6

Choose the cake with the best top, then put the other cake top-down onto a serving plate and spread with half the coffee icing. Sandwich together with the other half. Ice the top of the cake and decorate with the walnut pieces to serve.