Unsalted Butter 1 cup
Powdered Sugar 4 cups
Vanilla Extract 1.5 tsp
Milk 2-3 tbsp
Salt 1/8 tsp
You can cream the butter and sugar, but I don’t think it’s necessary.
Just mix everything in a bowl, scraping the sides down every 45 seconds. Start with 2 tbsp of milk, and add more if needed.
It’s surprising how much sugar can be absorbed by the butter.