Cut panettone into 16 (1/3-inch-thick) slices and toast lightly. Spread Nutella on toasted panettone. Arrange slices in slightly overlapping single layer in greased 13x9-inch ceramic baking dish.
Bring whipping cream and milk to boil in saucepan. Beat eggs, egg yolks, sugar and vanilla with electric mixer until mixture starts to ribbon.
Remove milk mixture from heat and add to egg mixture. Mix well. Strain custard mixture and pour over bread slices in baking pan to cover. Bake bread pudding in water bath (place baking pan in larger pan with hot water halfway up sides) at 350° F for 45 minutes.
Remove from oven and let rest before serving.Makes 4 Source: