Sift together flour, bicarb soda, salt and the three spices then set aside. Mix until blended the copha, sugar, molasses and buttermilk. To this add the flour mixture, the walnuts, the raisins and peel. Mix until well combined.
Turn dough onto a large sheet of greaseproof paper or foil. Shape into a roll 5cm in diameter. Wrap in the paper or foil and refrigerate for several hours or overnight (or even up to two weeks).
About 15 minutes before baking time turn on oven and pre-heat to 180 degrees C. Grease baking trays.
Slice chilled dough 1cm thick and place on greased baking tray. Bake about 15 minutes or until done.