This is a recipe for a rich baked good, "Caramel & Chocolate Cake," where rich chocolate and bittersweet caramel blend together perfectly. First, make a caramel sauce with water and granulated sugar, then add heavy cream and milk and simmer until thickened. Next, melt the couverture sweet chocolate in a double boiler, then add the caramel sauce, beaten eggs, sifted cake flour, and room temperature unsalted butter in that order, mixing carefully after each addition. Pour the smooth batter into a loaf pan and bake in a double boiler until moist. Chilling it in the refrigerator overnight will result in an even more flavorful and smooth cake. This is a truly authentic treat perfect for a home café or for entertaining guests.