Preheat oven to 350 degrees. Grease a loaf pan.
Remove the stems from the oranges and cut into quarters. Remove seeds. Puree in food processor or blender until smooth. You should have about 2/3 cup of orange puree.
Add egg, milk and melted butter and pulse a few times until combined.
In a mixing bowl, whisk together flour, baking powder and sugar. Add liquid and fold until moistened. If batter is too dry add additional milk a tablespoon more at a time.
Fold in chopped cranberries.
Pour batter into prepared loaf pan. Bake at 350 degrees until toothpick inserted in the center comes out clean.