1Preheat oven to 350 degrees F (175 degrees C). Grease a 9x5-inch loaf pan.
2Sift flour, white sugar, brown sugar, baking powder, baking soda, and salt together in a large mixing bowl. Mash butter into the flour mixture with a pastry cutter until the mixture resembles coarse cornmeal.
3Stir orange juice, egg, vanilla extract, and orange zest together in a small bowl; add to flour mixture and stir just until the dry ingredients are moistened and batter-like. Fold cranberries and walnuts through the batter; spoon into the prepared loaf pan, spreading so the corners and sides are slightly higher than the center.
4Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 1 hour. Cool in the pans for 10 minutes before removing to cool completely on a wire rack.
Footnotes
Cook's Note:
When doubling recipe, use 3 eggs instead of just 2.