01 - Preheat the oven to 350°F. Grease and flour a 9x5-inch loaf pan or line it with parchment paper.
02 - In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until evenly combined.
03 - In a separate bowl, whisk the milk, oil or melted butter, egg, vanilla extract, and orange zest until smooth.
04 - Pour the wet ingredients into the dry ingredients and gently stir until just combined, avoiding overmixing.
05 - Fold in the cranberries and nuts if using, distributing them evenly through the batter.
06 - Pour the batter into the prepared loaf pan and spread evenly with a spatula.
07 - Bake for 50 to 55 minutes, or until a toothpick inserted in the center emerges clean.
08 - Allow the loaf to cool in the pan for 10 minutes, then remove and cool completely on a wire rack before slicing.