Place the cranberries in a heavy bottomed saucepan with the sugar, orange zest, orange juice, and cinnamon stick. Mix well.
Turn on the heat to a medium heat level.
Be sure to put the lid on the pot and cook for 15 minutes.
Stir every few minutes to make sure the cranberries do not stick to the bottom.
Remove the cranberries from the stovetop - check to see if all the cranberries have all popped. If not, cook for a few more minutes.
The sauce will be very loose.
But as it cools, the sauce will thicken up significantly.
After the sauce has cooled completely, you can add water a little bit at a time if you want to thin out the texture.
Remove the cinnamon stick.
Serve the cranberry sauce at room temperature or slightly chilled. Enjoy!