Melt together the semi-sweet chocolate pieces and the Kahlua over very low heat and set aside. (I use the microwave.) In blender, blend whole eggs, egg yolks, vanilla, and sugar. Blend for 2 minutes; add heavy cream and blend for 1 minute longer. Add chocolate and Kahlua mixture and blend until smooth. Chill about 3 hours. Makes about 5 champagne glasses. Serve with whipped cream. (I make ahead 1 day and put in Keebler chocolate pie crust. Its yummy!)