Preheat oven to 350, and butter a loaf pan.
In a bowl mix together sugar, orange juice, orange zest, butter and egg. Add remaining dry ingredients (not cranberries yet), and stir until most of the flour is incorporated.
Add in the cranberries and stir until just combined. Don't overmix. Pour into loaf pan and bake 40-45 minutes, or until a tester comes out clean. Let cool in pan, then loosen around sides and remove.