How to Make It
Heat oven to 325° F.
Place the panettone in a large bowl.
In a medium bowl, whisk together the cream, milk, eggs, yolks, sugar, zest, and vanilla. Pour over the bread cubes. Let soak for 5 minutes, stirring gently 2 or 3 times.
Pour the mixture into a buttered 9-by-13-inch baking dish. Bake for 60 to 70 minutes. Serve warm.