Pre-heat oven to 350 degrees.
Grease and flower a bundt pan (get in all the grooves).
Beat cake mix, water, butter, orange zest and eggs with an electric mixer on low for 30 seconds, then on medium for 2 minutes.
Scrape bowl and fold in cranberries.
Pour into pan.
Bake for one hour and test with a toothpick.
Cool 10 minutes and then turn pan upside down on a rack or plate. Serve with orange sauce.