Cut up croissants into 1-inch squares and place them on a sheet pan lined with parchment paper, and place in the oven at 350° for 15-17 minutes or until golden brown and slightly crunchy.
In the meantime, cut the vanilla bean in half longways.
Add it to 6 cups of heavy cream in a large pot and scald the mixture on medium-low heat. You’ll know it’s scalded when you tilt the pot and see several bubbles forming on the pot's bottom.
Once scalded, add to a mixing bowl with 15 egg yolks and 1 cup of sugar and mix well.
Be sure to scrape all the goodness out of the center of the vanilla bean and add it to the mixture.
Once the croissants are browned, place them in a large casserole dish. Sprinkle the dried cherries on top.
Next, pour in the vanilla bean custard and fold it together with a rubber spatula until combined.
Cover it with foil and bake it in the oven at 350° for 45-50 minutes or until the custard is firm.
About 10 minutes before the bread pudding is finished, start making the zabaglione.
In a metal bowl, whisk together 4 egg yolks and 1/2 cup sugar.
Transfer it to a double boiler on high heat and add in the champagne while continuing to whisk.
Beat vigorously until thick and foamy. Takes about 6-8 minutes which is perfect because when this is done, the bread pudding will be finished as well.
Pour zabaglione over the bread pudding before serving.
Notes
Make-Ahead: This is meant to be served as soon as it is done baking.How to Store: You can cover it and store it for 3 to 4 days. This will freeze covered for up to 3 months. Thaw it in the refrigerator for 1 day before reheating.How to Reheat: Add the desired amount of bread pudding to a baking dish and cover it with foil. Bake it in the oven at 350° for 12 to 15 minutes or until hot. Serve with whipped cream and sauce.If you do not want to use all heavy cream in the custard, you can substitute half of it with whole milk.This can also be served with ice cream.