LINE 8x4-inch loaf pan with plastic wrap. Beat egg yolks and 1/2 cup whipping cream with whisk until well blended; set aside. Cook chocolate, corn syrup and butter in medium saucepan on medium heat until chocolate is completely melted, stirring constantly. Gradually stir in egg mixture; cook 3 min. or until thickened, stirring constantly. Cool to room temperature.

BEAT remaining whipping cream, sugar and vanilla in large bowl with mixer on high speed until stiff peaks form. Gently stir into chocolate mixture until well blended. Pour into prepared pan.

REFRIGERATE several hours or until firm. Unmould dessert onto serving plate before serving.