Preheat the oven a 180°C (375°F) Whisk energetically the 4 eggs with the sugar until they become light and fluffy. Use an electric hand mixer or a stand mixer for better results.
Add the zest of 3 oranges, honey, baking powder, dark chocolate chunks, and the flour and mix with a spoon until you get a sticky dough.
Wet your hands and make 2 or 3 loaves 2-3 inches (5-7 cm) wide and about 1 inch (3 cm) thick for the whole length of your baking tray. Keep each loaf at least 3-4 inches (8-10 cm) away from each other.
With wet hands or a wet spoon, smooth the top surfaces as much as possible, then sprinkle some sugar on top.
Bake in the preheated oven for about 20 minutes or until golden on top.
Let them cool for a few minutes than cut them into slices. Now place the Biscotti again on the baking tray with the cut side facing up and bake again for few more minutes to make them crunchy. If you want your Cantucci to be a little bit softer, you can skip the second bake.
Let them cool completely before serving.
You can store the Biscotti in tin cookie boxes or glass jars for several weeks.