Roughly chop the walnuts and add them in a large bowl. Add the flour, baking powder, powdered sugar, spices and candied fruits in the same bowl with the walnuts and mix well with you hands or with a wooden spoon.
Set aside and prepare the sugar syrup: In a medium pan pour the water and add the sugar; turn on the heat to low and stir frequently to melt the sugar. Turn off as soon as all the sugar is melted (In total it will take about 3-5 minutes).
Pour the sugar syrup over the other ingredients and mix with a wooden spoon until you get a sticky ball of dough. At some point you may work it with your hands if you prefer, but be careful since the sugar syrup may be still hot.
Pour some extra flour on a cutting board; make small balls of dough,the size of a golf ball and roll them in the flour until completely coated. Press them gently with your palm to make thick disks and place them in a baking tray lined with baking paper.
Bake the Cavallucci in the pre-heated oven for about 10-15 minutes.
Notes
The proportion of spices for Cavallucci is: -65% Coriander seeds -20% Cinnamon -10% Nutmeg -5% Anise