How to Make It
Preheat the oven to 350°. Butter a 9-by-13-inch glass or ceramic baking dish. Brush both sides of each bread slice with melted butter. Arrange the bread in the prepared dish in 2 even rows.
In a large bowl, whisk the whole eggs with the egg yolks until blended. Whisk in the granulated sugar, milk, heavy cream and vanilla. Strain the milk mixture over the bread, pressing on the slices to make sure they're evenly moistened.
Place the baking dish in a larger roasting pan and pour enough warm water into the pan to reach halfway up the side of the dish. Bake in the upper third of the oven for about 25 minutes, or until the top is lightly browned and the custard is set. Transfer the baking dish to a rack and let the custard rest for 15 minutes. Sift confectioners' sugar over the custard and cut into squares. Serve with berries.