You can use prepared frosting to give cakes fast, smooth and impressive top¬pings.  Simply remove the frosting’s lid and foil seal, then microwave the con¬tainer for 30 seconds.  Stir the frosting a bit and pour it over your cake. This is really a time-saver if you’re serving a cake directly from the baking pan.

If you remove the cake from the baking pan before frosting it. microwave the frosting for only 15 to 20 seconds.