Pre-heat oven to 165°C (325°F).

Grease a 9 x 5 inch loaf pan with extra butter and lightly dust with flour. Shake off the excess flour.

Sift flour, baking powder, baking soda and salt into a mixing bowl. Stir in the chopped walnuts. Set aside.

Dissolve instant coffee granules in hot water. Stir in the milk. Set aside.

Using a stand mixer fitted with a paddle attachment or handheld mixer fitted with beaters, cream butter and sugar until light and fluffy, on medium speed (speed 3 to 4 on my Kitchen Aid mixer). This may take 6 to 8 minutes.

Add eggs, one at a time, beating each addition until well incorporated.

Keeping a light hand, fold ⅓ of the flour-walnut mixture into the creamed butter mixture, followed by ½ of the coffee-milk solution. Do not over-mix the batter.

Fold in the next ⅓ of the flour-walnut mixture, followed by the remaining ½ of the coffee-milk solution. Again, without over-mixing the batter, fold in the last ⅓ of the flour-walnut mixture.

Lastly, fold in the vanilla extract until well incorporated.

Pour batter into greased pan and bake in slow oven for 50 to 60 minutes. Once the centre of the cake springs back when pressed, or a bamboo skewer inserted into the centre of the cake emerges free of cake batter, the cake is done.

Remove from the oven and leave the cake in the pan for 10 - 15 minutes before turning out onto a metal rack to cool completely.

Once the cake is completely cool, make the coffee glaze. Drizzle over the cake, and sprinkle walnuts over the top. Allow the glaze to firm up and set for clean slices.

In a small bowl, dissolve instant coffee granules in hot water.

In a mixing bowl, cut the butter into icing sugar with a wooden spoon or whisk.

Once the mixture resembles breadcrumbs, stir in the coffee solution, bit by bit, until you get a thick but pourable consistency. If you want the glaze more firm, add more icing sugar.