Preheat the oven to 350°F. Grease a 9-inch x 5-inch x 3-inch loaf pan or 8-inch tube pan. In a large bowl, sift together flour, baking powder, salt, and baking soda. Using a pastry blender or 2 knives, cut in butter until coarse crumbs form.
In a food processor or blender, process orange pieces until almost smooth. Pour into a glass measuring cup and add boiling water to make 1 cup. Transfer to a medium bowl and mix with cranberries, sugar, and egg.
Add fruit mixture to flour mixture all at once and stir just until blended. Fold in walnuts and spoon into prepared pan. Bake 1 hour. Cool bread in the pan on a rack 5 minutes before removing.