In a large bowl, combine the flour, baking powder, baking soda, allspice and salt and mix well. Cut the butter and shortening into small pieces and add to the flour mixture. Using your fingers, work the cold butter and shortening into the flour mixture until it resembles coarse crumbs. Add the egg, the buttermilk, the dried fruit and the walnuts and mix into the flour mixture until it is incorporated. Turn the dough out onto a floured surface and knead gently until the dough forms a smooth ball. Shape the dough into a round loaf. Place the dough onto a lightly oiled baking sheet. Score the top of the loaf with a very sharp knife. Place the loaf in the oven and bake for 40 to 45 minutes or until golden brown.