Step 1In a bowl, stir together the cream and milk. In a separate metal bowl or double-boiler insert, whisk together the egg, egg yolks and cornstarch.
Step 2In a heavy-bottomed pan, combine the water, sugar and salt, and cook over medium-high heat, stirring occasionally, until amber in color (careful not to burn), 2 to 3 minutes. Add the cream and milk mixture, and gently simmer for 5 to 7 minutes.
Step 3Temper the eggs: Slowly whisk the cream mixture into the eggs to form a custard base. Place the egg base over pan of simmering water (double boiler) and gently cook until the mixture is thickened and coats the back of a spoon (it should have a warm pudding consistency), 6 to 8 minutes. Whisk in the butter, liqueur and honey.
Step 4Strain the mixture and pour into 8 glasses. Chill, uncovered, until the custard is set, at least 4 hours.
Step 1Bring the cream to a boil and pour over the chopped chocolate, stirring occasionally until the chocolate is melted and the mixture is smooth. Set aside to cool.
Step 2Before serving, pour a layer (about 2 to 3 tablespoons, you may not use all of the ganache) over each set caramel budino, and top with a dollop of whipped sour cream and a sprinkling of chopped hazelnuts.