Method

• 1.
  Preheat oven to 200°C. Lightly grease a 25ml (5-tsp) 12-hole madeleine pan.
• 2.
  Place flour, baking powder, eggs, butter, half the lime zest, lime juice and 60g caster sugar in a bowl and whisk until smooth. Spoon 1 heaped tbs of batter into pan holes and bake for 8-10 minutes or until golden and cooked through. Invert onto a wire rack and stand to cool completely.

• 3.
  Meanwhile, to make the lime sugar, combine remaining 50g caster sugar and remaining lime zest in a bowl. To make the ruby red icing, combine icing sugar, chopped grapefruit flesh and grapefruit juice in a separate bowl.
• 4.
  To serve, dip the madeleines in icing, then scatter with lime sugar and stand on wire racks at room temperature to set.