Begin by placing 1 cup of softened unsalted butter in a large bowl. Using an electric mixer, beat the butter on medium speed until it becomes creamy and fluffy, which should take about 2 minutes.

Gradually add 4 cups of powdered sugar to the butter mixture. Start mixing on low speed until the sugar is fully incorporated to avoid any flying sugar clouds. Once combined, increase the speed to medium.

Now, measure out 2-3 tablespoons of heavy cream or milk, 1 tablespoon of vanilla bean paste or extract, and a pinch of salt. Pour all these into the bowl with the butter and sugar mixture.

Beat the mixture on high speed for about 3-5 minutes. Watch how it lightens and becomes fluffy. This step is crucial for achieving that airy texture.

Once the frosting has reached the desired consistency, use it immediately to frost cakes, cupcakes, or cookies. If needed, spread it smoothly with a spatula.

If you have any leftover frosting, store it in an airtight container. Place it in the fridge for up to a week or in the freezer for up to three months.