Add the 2 whole eggs to a small pot and cover them with cold water. Bring the water to a gentle boil over medium heat. When the water boils, lower the heat to a simmer and cook the eggs for 6 minutes. Remove the eggs from the pot and run them under cold water to stop them from overcooking.
In the bowl of an electric mixer fitted with a whisk attachment, add the 2 egg whites and beat until stiff peaks form, about 3 to 5 minutes. Gently fold the egg whites into the ricotta mixture with a rubber spatula, retaining as much fluffiness as possible. Transfer the mixture to the loaf pan. Put the pan into a shallow water bath and bake, undisturbed, for 50 minutes. Remove the pan from the oven and the water bath. Allow to cool 10 to 15 minutes before serving. Sprinkle with a touch of lemon zest and some chocolate over each individual portion.