Place softened butter in a large mixing bowl and beat until creamy.
Gradually add powdered sugar, mixing on low speed.
Pour in heavy cream and vanilla extract, then add a pinch of salt.
Beat on high speed until fluffy, about 2-3 minutes.
Scrape down the sides of the bowl as needed.
If too thick, add more cream, one tablespoon at a time.
Taste and adjust vanilla or salt if necessary.
Use immediately or store in an airtight container.