Beat softened butter for 2–3 minutes until light and fluffy.
Add sifted powdered sugar one cup at a time on low speed.
Add vanilla extract and salt.
Beat on medium-high for 3–4 minutes until smooth and fluffy.
Add cream one tablespoon at a time until desired consistency.
Taste and adjust sweetness or vanilla as needed.
Use immediately or store and re-whip before using.