When ready to bake, Preheat the oven to 350°. Place a roasting pan large enough to hold your baking pan in the oven and pour 1/2 inch of hot water into it.

In a large bowl, whisk the eggs and the egg yolks with the sugar and salt until lightened in color. While continuing to whisk, slowly add the milk, then mix in the vanilla.

Add the croissants, pressing them down into the mixture. Soak for about an hour, pressing down on the croissants several times.

Transfer half the mixture to a buttered 11 x 7″ (or reasonable substitute) casserolr. Sprinkle any of the additions you would like to use over the top. Finish by spooning the remaining mixture over top. Carefully place the dish in the pan of hot water and bake until golden and just set, about 50 minutes. Serve slightly warm or let cool completely. To store, refrigerate covered with plastic wrap for up to 3 days.