Photo: Hector Sanchez; Prop Styling: Buffy Hargett Miller; Food Styling: Marian Cooper Cairnes
Beat butter and salt at medium speed with a heavy-duty electric stand mixer until creamy; gradually add powdered sugar alternately with 4 Tbsp. milk, beating at low speed until blended and smooth after each addition. Stir in orange liqueur and vanilla. Beat in remaining milk, a few teaspoons at a time, until frosting reaches desired consistency.