MAKES ENOUGH TO ICE A 20CM ROUND CAKE PREP 15 MINS COOK 10 MINS
4 egg whites
11/4 cups caster sugar
330g unsalted butter, chopped, at room temperature
Place eggwhites and sugar in a clean, dry, heatproof bowl over a saucepan of simmering water (don’t let base of bowl touch the water). Whisk constantly for 6 mins or until sugar has dissolved and mixture is hot (70°C). Transfer bowl to an electric mixer. Beat on high speed for 10 mins or until mixture is thick and glossy and cooled. Reduce speed to medium. Gradually add butter, beating after each addition until smooth.