Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper for easy removal.
In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and orange zest until well combined.
In another bowl, beat the eggs, then add in the applesauce, vegetable oil, vanilla extract, and fresh orange juice. Mix until smooth.
Pour the wet ingredients into the dry ingredients. Gently fold to combine until just moistened. Do not overmix; a few lumps are okay. If using, fold in chopped cranberries and nuts.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake in the preheated oven for 55-65 minutes or until a toothpick inserted into the center comes out clean.
Once baked, remove the loaf from the oven and let it cool in the pan for about 10 minutes. Then transfer it to a wire rack to cool completely.
Notes
Slice the loaf and serve on a decorative platter; sprinkle with additional orange zest for a pop of color and aroma, or drizzle with a simple icing made from powdered sugar and orange juice.