Method
Preheat your oven to 350°F and grease a 9x5-inch loaf pan with butter or cooking spray.
In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until well combined.
In a separate medium bowl, whisk the orange juice, egg, vegetable oil, and orange zest until smooth and fully incorporated.
Pour the wet ingredients into the dry ingredients and stir with a spatula until just combined—the batter will be thick and slightly lumpy.
Gently fold in the chopped cranberries and walnuts until evenly distributed throughout the batter.
Transfer the batter to the prepared loaf pan and spread it evenly into the corners using your spatula.
Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.
Cool the bread in the pan for 15 minutes before transferring to a wire rack to cool completely.