Preheat the oven to 350 degrees F. Grease an 8-inch square pan, and have ready a larger pan (such as a roasting pan) as you will be baking the smaller pan in the larger.
Whisk the egg yolks and eggs together in a small bowl and set aside.
In a large saucepan, combine the cream, milk and sugar and cook over medium heat until bubbles begin to form around the edge, but not quite boiling. Stir in the white chocolate, then gradually add the egg mixture in a slow and steady stream, whisking constantly.
Remove from heat and stir in the vanilla extract (or paste).
Put the bread in the greased baking pan and gradually pour the egg mixture over the bread, pressing it down and making sure it all falls through the cracks. Let rest for 15 minutes.
Cover with aluminum foil and place in a larger pan (such as a roasting pan) filled halfway with very hot water. Transfer to the oven and bake until firm and, when touched in the middle, the custard does not show up on your finger, about 1 hour and 15 minutes.
As the custard bakes, keep checking the water level, adding enough so that it’s always at the half way point.
Serve warm with fresh berries or raspberry sauce.