Method

1. Preheat the oven to 170c (fan). Grease and line a 900g (2lb) loaf tin with baking parchment. Using electric whisk, beat together the butter, sugar and grapefruit zest for 3 to 5 minutes until light and fluffy, scraping down the sides occasionally. Then incorporate the eggs, one at a time.
2. Fold in the flour, salt and cardamom, then add the milk and vanilla until just combined. Carefully spoon the mixture into the loaf tin and bake for 45-50 minutes until a skewer inserted in the centre comes out clean.
3. After removing the cake from the oven whilst still hot, mix 75ml of the grapefruit juice with the granulated sugar. Pierce the cake with a skewer and spoon the juice and sugar mixture over the top making sure it evenly covers the top of the cake. Allow to cool before removing from the tin.
4. While the cake is cooling, make your meringue, add all the ingredients to a large metal bowl which fits snugly over a saucepan of gently simmering water.
5. Whisk with a hand whisk until the mixture reaches 70c on a thermometer or for at least 2 minutes until the sugar has dissolved. Transfer to a stand mixer and continue to beat on high for 8 minutes until the meringue has tripled in size and is smooth and glossy.
6. Transfer the mixture to a piping bag. Once the cake is cool, slice into servings and place on a plate. Add a dollop of icing in the centre of the cake and make a small divot in the icing with the back of the spoon. Spoon a teaspoon curd into the indentation to resemble an egg, then serve.