Chocolate Frosting

This is based on the chocolate frosting recipe that accompanies America’s Test Kitchen’s Yellow Cake recipe. NOTE: I halved the original recipe, so the quantities given below make enough for an 8x8 cake or 6 cupcakes. For a 9x13 cake or 12 cupcakes, double the quantities.


  • 4½ ounces confectioners’ sugar
  • ¾ ounce unsweetened cocoa powder
  • 4 tablespoons unsalted butter softened
  • 2 tablespoons hot water
  • ⅛ teaspoon table salt
  • 1 ounce bittersweet chocolate melted


  1. Combine confectioners’ sugar, cocoa, butter, water, and salt in bowl of stand mixer fitted with whisk attachment.
  2. Stir on low speed until combined, about 20 seconds.
  3. Increase speed to medium and continue to mix until smooth, about 1 minute, scraping down sides as necessary.
  4. Add chocolate, and beat on low speed until incorporated.
  5. Let sit at room temperature until thickened to spreadable consistency, 30-40 minutes.