This makes enough to cover one large cake or frost 18 – 20 cupcakes.
- 3 large egg whites, free range or organic
- 180g caster sugar
- 300g unsalted butter, at room temperature
- Pinch of fine salt
- Vanilla extract
Place 150g of the sugar in a small pan with 60ml of water and gently bring to the boil. Do not stir, but swirl around to dissolve the sugar. Leave the pan on a gently rolling boil, until it reaches 121c on a sugar thermometer. Have a bowl of cold water at the ready to plunge the pan into.
Whilst the syrup is on the hob whisk the egg whites in a free standing mixer until you have stiff peaks, and then gradually whisk in the remaining sugar. As soon as the sugar syrup reaches 121c, plunge the pan into the bowl of cold water for just a few seconds to cool quickly. Then, with the mixer on full speed, gently pour the sugar syrup into the egg whites in a thin stream until all mixed together (try not to get the sugar syrup up the sides of the bowl or on the whisk itself as it will stick to them, aim for the egg whites). Continue to mix for a further 8 – 10 minutes until the bowl is cool. Chop the butter into chunks and gradually whisk into the meringue, with the salt and a splash of vanilla. It may look like the mixture has split but keep mixing, you will end up with a smooth and fluffy buttercream.