How to make
Mix the flour and cocoa in a deep bowl. Add the instant coffee and baking powder. Add the sugar and add a pinch of salt.
In another bowl, beat the eggs. Add to the dry base along with the vanilla and stir until the mixture is homogeneous. Knead into a firm and thick dough.
Lightly chop the pistachios and dark chocolate and add them to the mixture, while stirring.
Form the dough into an oblong and flat cylinder with about a 0.6″ (1.5 cm) height. Place it in a baking pan onto baking paper and bake at 360°F (180°C) for 20 minutes.
Leave it to cool down and cut the cylinder into individual 0.4″ (1 cm) thick biscotti.
Place them back into the pan and bake the Cantuccini for another 8-9 minutes.
