• Preheat the oven to 170°C.
• Using a NutriBullet or a small food processor, quickly blitz the shelled pistachios so they are coarsely ground.
• Line the base of a 23 × 13 cm loaf tin with baking paper, then butter and flour the sides.
• Cream the butter, sugar and lemon zest using an electric mixer until light, pale and fluffy.
• Add the eggs one at a time, mixing well after each addition.
• Add the lemon juice and the yoghurt and mix gently to combine.
• Fold through the sifted flour, baking powder and sea salt, followed by the coarsely ground pistachios.
• Spoon the batter into the prepared loaf tin and smooth the top. Bake in the preheated oven for approximately 60–65 minutes. The cake is ready when a skewer inserted into the centre comes out clean, or when the internal temperature reaches 96–98°C using a probe thermometer.
• Allow the cake to cool in the tin for an hour before turning out onto a wire rack to cool completely.

For the Icing

• Place the sifted icing sugar in a bowl. Gradually stir in the lemon juice, then the cream, until you have a smooth icing that is thick but pourable.
• Set the completely cooled cake on a wire rack with a tray or baking paper underneath to catch any drips.
• Spoon the icing along the centre of the cake and gently encourage it to flow toward the edges using the back of the spoon. Allow some of the icing to naturally run down the sides of the cake.
• While the icing is still soft, scatter over the coarsely chopped pistachios.
• The icing will firm up within a couple of hours (but I never wait that long).
• The cake will keep, covered, at room temperature for up to three days, or refrigerated for up to one week.