Scald the 3 cups milk in a heavy-bottom medium saucepan over medium low heat with sugar and vanilla bean seeds. Discard the vanilla pod or place in sugar bowl for flavoured sugar. If using vanilla extract, add it in the end with the chocolate to prevent evaporation.
In a medium bowl, whisk together egg yolks, 1/4 cup milk and cornstarch. Add the hot milk mixture in a slow stream, whisking constantly and then pour back into pot.
Cook the pudding gently over medium heat, stirring constantly with wooden spoon for one to two minutes or until mixture thickens and boils. Change to a whisk towards the end of stirring to ensure a smooth cream. Remove from heat. Whisk in the chopped chocolate, butter and Frangelico. Divide pudding among six ramekins or small bowls and chill , preferably for three hours.
Heat sugar in a heavy-bottom pot until caramel colour. Remove from heat immediately and add 2/3 cup cream. Let stand for two to three minutes until bubbles subside. Cool, then set aside.
Whip cream until peaks begin to hold. Add the icing sugar and continue to whip until smooth.
To serve budino, drizzle the top of pudding with caramel. Sprinkle with fleur de sel and spoon a little whipped cream on top. Dust with cocoa.