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 mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until evenly blended.
03 - In a separate bowl, whisk the melted butter, egg, orange juice, vanilla extract, and orange zest until fully incorporated.
04 - Pour the wet ingredients into the dry mixture and stir gently until just moistened; do not overmix to maintain a tender crumb.
05 - Fold in the cranberries and nuts, if using, with care to evenly distribute without crushing them.
06 - Pour the batter into the prepared loaf pan and smooth the surface evenly.
07 - Bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out clean.
08 - Allow the loaf to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.