Preheat the oven to 350°F. Mist an 8½-inch x 4½-inch loaf pan with nonstick cooking spray, and set it aside. 

Place the dry ingredients in a large mixing bowl, and stir them together.  

Place the wet ingredients in a medium mixing bowl, and stir them together until they are well combined. 

Pour the wet ingredients into the dry ingredients. Mix just until the dry ingredients are evenly moistened. Fold the diced apple, raisins, and walnuts into the batter, making sure they are evenly distributed.  

Spoon the batter into the prepared loaf pan. Place the loaf pan on the center rack of the oven, and bake the bread for about 50 minutes, or until a cake tester inserted in the center tests clean.  

Remove the bread from the oven using oven mitts or pot holders. Turn it out of the loaf pan onto a cooling rack, and carefully turn the bread upright. Allow the bread to cool completely before slicing or storing it. Wrap the cooled bread tightly, and store it at room temperature for up to 3 days, or refrigerate it for up to 7 days.