5
For the frosting, add the softened unsalted butter and cream cheese to the bowl of your mixer and beat on high speed until it begins to thicken and fluff. Lower the mixer speed and carefully add in the confectioners' sugar. Once all the sugar is incorporated, turn the mixer back to high and continue whipping the frosting. Then, add in the pineapple juice, vanilla extract, and a pinch of salt, continuing to whip until the frosting is smooth, light, and fluffy.