How to Make It
Prepare the Cookies: Preheat oven to 350°F. Beat butter at medium speed with a heavy-duty stand mixer until creamy; gradually add sugar, beating well. Beat in orange zest, juice, and vanilla until fully incorporated.
Stir together flour and salt in a small bowl; gradually add to butter mixture, beating at low speed until blended after each addition. Place dough on a lightly floured surface, and roll to 1/4-inch-thick. Cut with a 2-inch round cutter. Place 2 inches apart on 2 baking sheets lined with parchment paper (about 14 per baking sheet). Reroll scraps once.
Bake, in batches, in preheated oven until lightly browned on bottom and around edges, 11 to 13 minutes. (Refrigerate second batch while baking first batch.) Cool on baking sheet 2 minutes. Transfer to a wire rack, and cool completely (about 30 minutes).
Meanwhile, prepare the Orange-Cream Cheese Frosting: Beat together cream cheese and butter with an electric mixer until light and fluffy. Gradually add powdered sugar, and beat well. Beat in zest and juice. Beat in 1 to 2 drops orange food color gel, if desired. Use immediately.
Spread about 1 tablespoon frosting on each cooled cookie, using a small offset spatula.