Step 1

Start by adding some water into a pot and place this over medium heat. Let this come to a simmer.

Step 2

In a bowl, add the egg whites, sugar and salt. Mix these together then place this bowl on top of the pot. Make sure that the simmering water isn't touching the bottom of the bowl. If it is, pour some of the water out.

Step 3

Keep heating this, whiles constantly stirring, until the mixture becomes smooth. To check this, rub some of the mixture between your fingers. If you can't feel any sugar any more, it's done.

Step 4

Pour this into your stand mixer bowl and then using the whisk attachment, whip it on high speed for about 10 minutes.

Step 5

After 10 minutes feel the sides of your bowl. If your bowl no longer feels hot, you can start adding in the softened butter.

Step 6

Whiles your mixer is running, at a lower speed, add in the butter bit by bit. Then once all of it has been added, keeping whipping it until you get a thick smooth buttercream. Now just mix in the vanilla.

Step 7

At this point it is done but it will have a lot of air bubbles so if you want to get rid of these, add a few spoonfuls of the buttercream into a separate bowl and melt this in your microwave. Pour this melted buttercream back into the rest, switch your mixer to a paddle attachment and mix the buttercream on low speed for 10 minutes.

Step 8

Then that is it, pipe it onto some cupcakes or use it on a cake and enjoy!