Combine the cranberries, water, finely grated orange peel, and stevia (or your chosen sweetener) in a large saucepan. Set the pan over medium heat and stir to mix all the ingredients. Raise the heat to medium-high, bringing the mixture to a boil. Once boiling, reduce the heat to medium-low and continue to cook, stirring occasionally. Cook for about 5 to 10 minutes, or until the cranberries have burst and the sauce has thickened to your preferred consistency.

If you prefer a smoother consistency, use a fork or potato masher to mash the cranberries further while the sauce is still hot. Remove the saucepan from the heat and stir in the vanilla extract and ground cinnamon, if using. I like to add both vanilla and cinnamon for an extra layer of warmth and aroma, but they're totally optional. Stir well to combine.

Let the cranberry sauce cool completely in the pan; it will continue to thicken as it cools. Once cooled, transfer it to an airtight container and refrigerate. The sauce will keep well in the refrigerator for up to 2 weeks, making it a convenient make-ahead option for the holidays.