Preheat the oven to 275°F. Stand the bread slices on a baking sheet and bake for 15 minutes, or until dry but not browned. Transfer the bread to a 13- x 9- x 2-inch baking dish in an even layer. Increase the oven temperature to 350°F.
In a large saucepan, heat the cream with the milk and sugar until hot but not steaming. Remove from the heat, add the white chocolate, and stir until melted.
In a large bowl, beat the eggs with the egg yolks. In a slow, thin stream, whisk the hot cream into the eggs until smooth. Pour the custard over the bread and let stand until soggy, about 20 minutes. Press the bread into the custard occasionally.
Cover the pudding with foil and bake for 1 hour. Remove the foil; bake for 20 minutes longer, or until golden and puffed. Let cool for at least 20 minutes.
Bring the cream to a boil in a small saucepan. Remove from the heat, add the white chocolate, and stir until completely smooth.
Cut the bread pudding into squares and decorate with the chocolate shavings. Serve warm, with the white chocolate sauce.
