The BEST Whipped Vanilla Buttercream frosting!
Beat butter in bowl of stand mixer with whisk attachment on medium-high speed until light and fluffy. (about 3 minutes)
With the mixer on low, slowly add in confectioners sugar , milk, and salt; frequently scrape sides and bottom of the bowl.
Once incorporated, whip frosting for at least 3 minutes on medium high to high. (My mixer went for 7 minutes)