In a large bowl, beat together butter, orange zest, vanilla extract, and salt with a mixer at medium speed until smooth. Add cream cheese, beating until smooth. Gradually add confectioners’ sugar, beating until combined. Continue beating until light and fluffy, 2 to 3 minutes, adding milk if necessary.
Recipe by TeaTime Magazine at https://teatimemagazine.com/orange-cake-with-orange-buttercream-frosting-recipe/