For about 30 cantucci:
Preheat the oven to 190 C (170 C fan) and line a baking tray with a baking parchment.
Place all the ingredients, apart from the walnuts, into a large bowl and work the ingredients in your hands, until obtaining a smooth homogeneous and elastic dough.
Now add the walnuts and kneed the dough for a short while, making sure that the walnuts are well combined and distributed within the dough. Form a bowl, which you will now cut in half.
Shape both halves into sausage shaped logs, about 4-5 cm in diameter. Place them on the prepared tray, leaving some space in between, and press gently on top.
Bake in the preheated oven for 20 minutes. The dough should be soft in the middle, but firm enough to cut into slices.
Take the tray out from the oven and let the rolls cool down a little.
Lower the temperature down to 170 C (150 C fan).
Carefully lift the rolls and slice them (1-1.5 cm thick) with a very sharp knife.
Put the slices back on the tray and bake again for a further 10-15 minutes, turning them half way through. The cantucci should be crisp and dry by now.
Transfer the biscuits onto a wire rack and let them cool down completely.
The cantucci store very well in an airtight container.