1. Roughly chop the cranberries and pistachios with a knife or a food processor, then set aside. Preheat the oven to 175°C/347°F.
2. In one bowl, thoroughly mix the flour, baking powder, and salt.
3. In another bowl, use an electric mixer to cream the soft butter and sugar until fluffy.
4. Add the egg and vanilla extract to the butter-sugar mixture and mix well.
5. Add the dry ingredients to the butter-egg mixture, along with the chopped pistachios and cranberries. Mix everything until you get a smooth dough. Only stir until no flour streaks remain.
6. Place the dough onto a baking tray lined with parchment paper. Lightly dust your hands with flour and shape the dough into a flat, long rectangle (about 20-25 cm long and 6 cm wide).
7. Bake the dough piece for about 30 minutes. Remove it from the oven and let it cool slightly.
8. Use a bread knife or sharp knife to slice the baked dough into pieces (about 1.5–2 cm thick).
9. Place the biscotti slices cut side down back onto the baking tray.
   • For a softer version: Bake each side for 5 minutes.
   • For a crunchier version: Bake each side for 10 minutes.
10. Dip half of the biscotti in melted white chocolate and sprinkle with chopped pistachios. Let them cool on a wire rack until the chocolate hardens.