"Chocolate is chocolate but this is heaven!!" In a heavy medium saucepan, melt chocolate and butter over low heat, stirring often. Stir in sugar, corn syrup and 2/3 cup half and half. Stir over medium-low heat until mixture comes to a boil. Simmer 4 minutes without stirring; set aside. In a small bowl, beat eggs until blended. Stir in 1/2 cup hot chocolate mixture. Cook and stir over medium heat until slightly thickened, about 1 minute. Cool to lukewarm. Stir in vanilla, 1 1/3 cup half and half and whipping cream. Pour into ice cream cannister. Freeze in ice cream maker according to manufacturers directions. Makes: 2 quarts