In double boiler or heavy saucepan, melt together chocolate, corn syrup and butter
until they are bubbling slightly.
While that is melting, beat together the 1/2 cup heavy cream with the egg yolks.
When chocolate mixture is melted and mixed and slightly cooled, slowly add egg yolk
mixture, beating continuously. It's important to mix the eggs in slowly and
beat well as you wouldn't want scrambled eggs. Cook for 3 minutes.
Let cool to room temperature, whisking occasionally.
Beat the 1 1/2 cups heavy cream with
the confectioners' sugar and vanilla extract until soft-medium peaks form. Fold
this into the chocolate mixture until no streaks of white appear. Pour into a loaf
pan, which has been lined with plastic wrap.