1: Preheat the oven to 180°C/Fan 160°C/Gas 4. Grease a 1kg (or 2lb) loaf tin with butter and line with baking paper

2: Put all the cake ingredients, except the walnuts, into a large bowl and beat, using an electric whisk, until smooth. Fold in the walnuts, using a spatula or large metal spoon.

3: Spoon the cake mixture into the prepared loaf tin. Bake on the middle shelf of the oven for 40–45 minutes. To check the cake is cooked, insert a skewer into the middle; it should come out clean.

4: Meanwhile, for the praline, place the walnuts on a baking tray lined with baking paper. Tip the caster sugar into a small heavy-based saucepan and place over a high heat. Swirl the pan as the sugar melts and the sugar syrup colours to form a caramel. When the caramel reaches a deep golden-brown colour, carefully pour it over the walnuts and then leave the praline to cool and set.

5: Once the cake is cooked, take it from the oven and leave to cool in the tin for 5 minutes, then remove and place on a wire rack. Leave to cool completely, then transfer to a board.

6: To make the coffee icing, in a bowl, whisk the butter, icing sugar and coffee together until soft and creamy.

7: Spread the coffee icing over the top of the cake and swirl decoratively with a palette knife. Roughly chop the walnut praline and sprinkle on top of the cake to finish.