Chop the white chocolate, then melt in a double boiler on the stove, or simply use the microwave: Place chopped white chocolate in a microwave-safe bowl (I usually use a glass liquid measuring cup), and microwave in 20-second increments, stirring after every 20 seconds until completely smooth. Set it aside to cool at room temperature for 20 minutes. (Be sure the melted white chocolate has cooled for 20 minutes, so it’s still melted but not scorching hot, which would melt the butter.)

In a medium bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed for 1 minute. Switch the mixer to low speed and slowly add the confectioners’ sugar.

Stir the cooled white chocolate so that it is smooth, and then add it to the butter/sugar mixture. Switch the mixer to medium speed and beat for 2 minutes until combined and creamy.

Add the cream, vanilla extract, and salt. Beat for 1 minute until combined. Taste. Add 1 more Tablespoon of heavy cream/milk if needed to thin out, if desired. Add another pinch of salt if frosting is too sweet.

Use immediately or cover tightly and store for up to 1 week in the refrigerator or up to 3 months in the freezer. After freezing, thaw in the refrigerator, then beat the frosting on medium speed for a few seconds so it’s creamy again. After thawing or refrigerating, beating in a splash of heavy cream or milk will help thin the frosting out again, if needed. (It stiffens in the refrigerator.)