Ingredients

　　4 tablespoons (1/2 stick) unsalted butter, room temperature

　　1/2 cup plus 2 tablespoons sweetened condensed milk (7 ounces)

　　Pinch of coarse salt

　　3/4 cup confectioners’ sugar, sifted

　　With an electric mixer on medium-high speed, whisk together butter, condensed milk, and salt until smooth. Whisk in confectioners’ sugar, 1/4 cup at a time, until combined, then whisk on high speed until thick and smooth. Use immediately.

　　Martha Stewart's Cupcakes