1

Preheat the oven to 190°C, fan 170°C, gas mark 5. Sift the flour and 50g icing sugar into a bowl and set aside.

2

In a large bowl, whisk the egg whites with an electric whisk until foamy. Whisk in the cream of tartar and salt, then gradually whisk in 150g icing sugar, one spoonful at a time, until stiff peaks form. Make 60ml coffee with 1 teaspoon instant coffee granules, then whisk this into the egg white mixture along with the vanilla extract.

3

In 3 batches, fold the flour mixture into the meringue mixture, using a metal spoon, until there are no lumps – be careful not to overmix. Scrape into an ungreased 24cm ring tin and bake for 30-35 minutes, or until puffed and golden.

4

Turn the tin upside down on a wire rack and leave to cool completely. Run a palette knife around the tin to loosen the cake and gently let it drop out. Set aside, base-side up, on a cake stand.

5

To make the glaze, make 1½ tablespoons coffee with ¼ teaspoon instant coffee granules, then stir into 90g icing sugar until smooth and combined. Pour over the surface of the cake, allowing it to drip down over the sides, then scatter over the shaved toasted walnuts.