In a large bowl, mix flour, sugar, baking powder, salt and bakind soda. Add butter and, with a pastry knife or 2 knifes, work the preparation until it has the texture of rough crumbs. Add egg, zest and orange juice and stir until preparation is homogeneous, without stirring too much. Add cranberries and walnuts by folding delicately.
Pour the dough in a loaf pan of 9" x 5", lighly greased. Cook in the preheated oven of 350 F for about 1 hour or until a toothpick inserted in the center of the loaf comes out clean. Let cool on a rack for 10 minutes.
Remove from the pan and put on the rack and let cool completely.