in a bowl combine chocolate, butter, and vanilla.
Heat cream until just before boiling, then pour over chocolate. Let sit for a minute, then slowly stir until everything is combined and mixture is smooth.
For a ganache coating: pour chocolate mixture directly over your dessert (ie. cake, cheesecake, etc).
For a whipped frosting: Chill in fridge until set, about 1 hour. Using a hand mixer, beat chocolate until light and fluffy. Spread over dessert.