This is my favourite chocolate frosting recipe, not too sweet, not too cocoa-ey and makes enough to fill and decorate a two layer chocolate cake =)
1/2 cup butter
2/3 cup cocoa
3 cups icing sugar
1/3 cup 10% cream
1 tsp vanilla
Beat butter until light and creamy.
Gradually add in the cocoa/icing sugar and alternate with the cream.
Add the vanilla and beat until the desired consistency.
Bear in mind, the longer you whip it up the lighter in colour it will get.
Keeps in the fridge for a couple of days if needed, but i tend to use it all up =)