MICROWAVE Choco Bake and butter in uncovered, microwave-safe bowl on HIGH (100%) power for 30 seconds; stir. If necessary, microwave at additional 5- to 10-second intervals, stirring just until butter is melted.
TRANSFER mixture to small mixer bowl; cool to room temperature.
BEAT sugar, 4 tablespoons milk, vanilla extract and salt into chocolate mixture just until spreading consistency. Up to 2 tablespoons milk can be added for a creamier frosting.
FOR THE SAUCEPAN METHOD:
MELT Choco Bake and butter in small, heavy saucepan over lowest possible heat, stirring until smooth. Remove from heat. Transfer to small mixer bowl; cool to room temperature. Proceed as above.
Recipe makes 2 cups total.