Place the walnuts in a food processor, pulse until you get a finer texture, and set aside.
Sift and combine the flour, baking powder, cinnamon powder, and ground cloves in a medium-sized bowl.
In a larger mixing bowl, beat the sugar and softened butter.
Add the eggs one at a time, mixing in between additions.
Add the dry ingredients from earlier (flour, spices, etc.) and combine everything.
Fold the chopped walnuts and grated chocolate into the walnut cake batter.
Pour batter into the greased cake pan, then use an angled spatula to even the top.
Place the karidopita pan in the lower part of the oven for 40 to 45 minutes or until a toothpick comes out clean when inserted.