Have a deep, cold, silver dish ready, fifteen inches long by eleven wide. Put into a vessel four ounces of powdered sugar. Break twelve fresh eggs, drop the whites into a copper basin, and the yolks of five into the vessel containing the sugar, reserving the other seven yolks for other purposes. Add to the vessel containing the sugar and yolks a light teaspoonful of vanilla essence: now with the wooden spatula, begin to beat the yolks with the sugar as briskly as you possibly can for fifteen minutes. Lay it aside. Then with the aid of a pastry wire-whip, beat up to a very stiff froth the twelve egg whites in the copper basin, which will take from twelve to fifteen minutes. Remove the pastry wire-whip; take a skimmer in the right hand, and with the left take hold of the vessel containing the preparation of the yolks and sugar. Gradually pour it over the whites, and with the skimmer gently mix the whole together for two minutes. The preparation will now be of a light, firm consistency. Now, with the aid again of the skimmer, take up the preparation and drop it down in the centre of the cold dish, ready as above mentioned, taking special care to pile it as high as possible, so as to have it of a perfect dome-shape; a few incisions can be made all around, according to taste; immediately place it in a moderate oven to bake for fifteen minutes. Take it out of the oven, and, in order to avoid burning or soiling the table-cloth, lay the dish containing the omelet on another cold one, liberally sprinkle powdered sugar over it, and immediately send to the table.

N. B. - Special care should be taken when piling the preparation into the cold, silver dish; and the making of the incisions should be done as rapidly as possible, so that success will be certain. When desired, the vanilla essence can be substituted with the same quantity of orange-flower water.