In a stand mixer, cream the butter on medium speed until it is very light in texture – about 2 minutes.
Add the confectioner’s sugar, vanilla and salt and mix on a low speed until the sugar and butter are blended, scraping down the bowl as needed.
Increase the speed to high and whip the buttercream about 5 minutes until very smooth, light and a good spreading consistency. Adjust with cream or icing sugar as needed.