In a large bowl, combine the flour, baking powder, baking soda, salt and sugar.
In another bowl, beat the eggs. Add the orange juice, orange zest, vanilla and butter. Whisk until well combined.
Add the dry ingredients to the wet ingredients. Blend until smooth.
Fold in the cranberries and if you would like, you can also add nuts in this step.
Grease a mini loaf pan or a full size loaf pan with cooking spray. Scoop batter into the loaf pans filling about 2/3 full. This recipe made 6 mini loaves or 1 full loaf.
For mini loaves: Bake at 350 F for about 20-25 minutes or until a toothpick inserted in the center comes out clean. For a full loaf: Bake at 350 F for about 60-70 minutes or until a toothpick inserted in the center comes out clean.
Remove from oven, allow to cool in pan for 10 minutes and then remove to wire cooling rack.