Preheat Oven and Grease Pan:
Heat oven to 350°F (175°C). Coat a 9×5-inch loaf pan with grease.Mix Dry Ingredients:
In a bowl, stir together flour, sugar, baking powder, and salt.Whisk Wet Ingredients:
In a separate bowl, beat egg, then whisk in milk, oil, and vanilla.Combine Wet and Dry:
Add wet mixture to dry mixture and stir just until combined; do not overmix.Fold in Cranberries and Nuts:
Gently incorporate cranberries, plus nuts and orange zest if desired.Pour Batter into Pan:
Transfer batter to the prepared pan and level the surface.Bake Until Toothpick Clean:
Bake for 50–60 minutes, or until a toothpick inserted in the center emerges clean.Cool Bread in Pan:
Let the bread cool fully in the pan set on a wire rack before cutting.Serve with Butter or Glaze:
Present warm with butter, honey, or a thin glaze.