Preheat oven to 150°C. Butter and line a 10-inch springform pan with parchment paper, on the sides and the bottom. Butter parchment (or spray with food release).
In a large bowl, combine nuts, peel, raisins, flour, cocoa and spices.
In pot over medium heat, cook sugar, honey and butter until it reaches a temperature of 120°C (about 8 to 10 minutes). Working quickly, pour syrup over nut mixture, stirring until combined.
The panforte stiffens quickly, so immediately spoon mixture into pan and spread to edges of pan.
Bake for 30 minutes. Allow to cool in the pan completely. Wrap and store at room temperature.
Panforte is best served in thin slices (as you would serve fruitcake).