1. In the bowl of a stand mixer fitted with the paddle attachment, beat butter and salt at medium speed until smooth and creamy, 1 to 2 minutes. With mixer on low speed, add confectioners’ sugar, 1 cup (120 grams) at a time, alternately with cream, beginning and ending with confectioners’ sugar, beating until combined after each addition. Beat in vanilla. Scrape paddle and bottom and sides of bowl. Increase mixer speed to medium-high, and beat until pale and fluffy, 1 to 2 minutes. Use immediately.