Ingredients
Whipping cream (heavy ) 2/3rd cup
Semi sweet/ dark baking chocolate  6 ounces/170 gms
Butter 2 tbsps

Method:
1) Heat the whipping cream & butter until hot but not boiling, in a saucepan.
2) Chop the chocolate very finely & keep in a dish. Pour the hot cream over the chocolate & let it stand for 5 minutes. Blend well. Ganache is ready when the mixture moulds slightly when dropped from a spoon. The longer you keep it, the firmer it gets.
3) To frost a cake, place the cake on a wire rack. Pour ganache in centre of the cake, tilt wire rack , so that it flows evenly over all sides of the cake. Frost as required.

Note:
To make ice cream toppings etc for a thinner ganache add a little more whipping cream. For a thicker ganache to frost a cake, reduce whipping cream & increase chocolate.