This is the recipe for "Gâteau Magique," a magical cake that separates into three layers—sponge, custard, and fudge—from a single batter. The batter is made by mixing egg yolks, sugar, melted butter, cake flour, and milk, then gently adding whipped egg whites, and baking it slowly in the oven. It's a visually appealing and enchanting dessert that offers a delightful combination of fluffy, creamy, and moist textures all at once.