With a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on medium speed until creamy, about 2 minutes. Add the peanut butter, confectioners’ sugar, heavy cream, vanilla extract, and salt with the mixer running on low. Increase to high speed and beat for 3 full minutes. Add up to ¼ cup more confectioners’ sugar if frosting is too thin or another Tablespoon of cream if frosting is too thick.
Cover tightly and store for up to 1 week in the refrigerator.
