Step 1

In a standing mixer fit with the paddle attachment on medium-high speed, cream butter until pale and fluffy, about 3 minutes.

Step 2

Reduce mixer speed to low. Add 4 cups powdered sugar, cream, vanilla, and salt (if using). Continue mixing 2 to 3 minutes longer. If the frosting seems too soft, add the remaining powdered sugar 2 tablespoons at a time.

Step 3

Cover and refrigerate the frosting until ready for use.