Have leftovers or making ahead? Lay extra slices of fully prepared Cereal Crunch Brioche French Toast on a parchment-lined sheet pan and pop into the freezer, uncovered, for about 45 minutes to one hour. Wrap or bag individual slices in Ziploc bags and store in the freezer. To serve, just pop the slices into a toaster oven or traditional oven, preheated to 350℉ for 10 minutes, rotating half-way through.