Beat butter, sugar and egg until creamy. Reduce to low; add flour, orange juice, baking powder and salt. Beat until well mixed. Divide dough into thirds & wrap. Refrigerate until firm (2-3 hrs).

Heat oven to 400 deg. On a lightly floured surface roll out the dough one third at a time into ⅛ to ¼ in thick. Cut with a 3 in cookie cutter. Place on a baking sheet 1 in apart. Bake for 6-10 min or until edges are golden. Cool completely before frosting.

Beat butter and sugar until fluffy. Add in vanilla. Beat in milk, one tablespoon at a time until desired thickness is reached (spreadable, but not too thick).