In a mixing bowl, beat the softened unsalted butter using an electric mixer on medium speed until smooth and creamy, about 2-3 minutes.

Gradually add the powdered sugar, one cup at a time, mixing on low speed to avoid a sugar cloud. Once incorporated, increase to medium speed until fluffy.

Add the heavy cream, vanilla extract, and a pinch of salt. Beat on medium-high speed for an additional 2-3 minutes until the frosting is light and fluffy.

If the frosting is too thick, add a little more cream; if it's too thin, add more powdered sugar, adjusting until you reach your desired consistency.

Use a spatula to frost your cake or cupcakes, or store the frosting in an airtight container in the refrigerator until ready to use.

For variations, consider adding cocoa powder for chocolate frosting, or fruit purees for a fruity flavor. You can also color the frosting with food dye for special occasions.

Leftover frosting can be stored in the refrigerator for up to a week. Make sure to re-whip before using it again.