Combine almonds, cashews, hazel nuts and candied peel.
Add the spices, flour and cocoa powder.
Melt chocolate on a double boiler and stir in the nut and flour mix.
Pre heat oven to 180 degrees C.
Line a loose bottom tin with parchment paper.
Stir sugar ,honey and butter over medium heat and bring to a boil. Do not stir.
Boil till the temperature reaches 240 degrees F / 115 degrees C. Check using a candy thermometer.
Remove from heat.Pour over the mix.
Mix everything very well, at this point you have to be quick, the mix can turn hard.
Transfer to the prepared pan smoothing it with wet palms or spatula.
Place cake in center of middle oven rack. Bake 30 minute or until panforte just starts to simmer around edge of pan.
Remove from oven; cool completely .
Push up the cake from bottom, and remove the parchment paper.
Sprinkle icing sugar all over and rub it gently with hands.
Cut into wedges.
The cake can be frozen upto six months.