If you don't have panettone, substitute thick slices of another egg-enriched bread, such as brioche or challah.
Serving: Serve the French toast warm from the skillet with maple syrup, agave nectar, or your favorite topping for breakfast. (Blueberry compote or sauteed apples are also nice.) A little pat of butter could also go on top as well. It can be served for dessert, as the French do, which is called pain perdu (lost bread), along with a scoop of ice cream and some caramel sauce.