01 -
Toss the softened butter into a stand mixer bowl or a large mixing bowl.
02 -
Set the mixer to medium-high and whip the butter for about 5 minutes. This will help make it super airy and soft.
03 -
Slowly add the icing sugar in three parts. Mix for about 1–2 minutes per round. Make sure to scrape down the bowl so everything blends perfectly.
04 -
Stir in the vanilla and milk. If you're piping the frosting, use less milk, but if you're spreading it, add a little more.
05 -
Scrape down the sides once more and give everything a last spin. It's now perfect to frost your cakes or cupcakes.
06 -
You can save the frosting at room temperature for 3 days or pop it in the fridge for up to a week.