Smooth and creamy cupcake buttercream

For cupcake recipe click here

100ml water (1dl)

10oz (300g) caster sugar 

5 large egg whites

500g unsalted softened butter

Pinch of salt

1tsp vanilla extract

Paste food colourings if you want to colour it

• You do need a candy thermometer for this or one that can rest in a saucepan and will reach above 120 degrees C. 
• Caster sugar is a finer sugar than regular granulated sugar. Regular sugar can be used but may take longer to dissolve. 

1. Fill a large bowl with cold water (large enough to fit your saucepan in as you'll need to plunge it in cold water later).

2. Pour 100ml water into a saucepan and add 250g (8oz) caster sugar. Place the saucepan on the hob and stir until the sugar dissolves completely. Bring the syrup to a boil and use a pastry brush to brush down any sugar that sticks to the side of the pan. (I never needed to do this). Stick a thermometer in the pan and boil the mixture rapidly until it reaches 121 degrees C. 

3. While the syrup boils, beat the egg whites until you get stiff white peaks when lifting the mixer out. Gradually mix in the rest of the sugar. About 1-2 tbsp at a time and mix for at least 4 seconds before adding more. The meringue should be white and glossy when done right. 

4. As soon as the syrup reaches 121 degrees C, take the pan off the heat and plunge it into the large bowl of cold water, to avoid it getting any hotter. Plunge for a few seconds, but not for too long as the syrup will thicken and become difficult to pour. 

5. With the mixer on full speed, slowly pour in the syrup in a thin stream. Take care to pour it between the edge of the bowl and the whisk, as it will otherwise either stick to the side of the bowl and set, or it will splatter and make a mess on the whisk. If the syrup becomes to thick, return to the hob for a short while to thin it. Continue to whisk until the bowl (and the mixture) feels just lukewarm. 

6. Gradually whisk in the soft butter and then add salt and vanilla. If the egg white mixture has not cooled down enough, it will melt the butter, and you don't want this to happen!

The meringue might collapse a little and may look like it's curdled, but keep whisking until it returns to being creamy. 

7. Add desired paste colouring, and ice your cupcakes. 

Tip: Make sure your cupcakes have cooled when piping your buttercream, as it will otherwise melt.