1. Combine sweetener, water, freshly squeezed orange juice, and orange zest in a medium saucepan. Stir thoroughly and bring to a gentle simmer over medium heat to dissolve the sweetener and release the citrus aroma.
2. Add fresh or frozen cranberries to the simmering mixture. Allow the sauce to come to a rolling boil, then reduce to a low boil or simmer. Cook for 8-10 minutes, stirring occasionally, until the cranberries begin to burst and the sauce starts to thicken.
3. Taste the sauce and adjust the sweetness to your preference by adding more of your chosen sweetener if needed. Stir well after any adjustments.
4. Add optional ingredients such as a cinnamon stick, a splash of vanilla extract, or a tablespoon of your choice of whiskey, brandy, bourbon, or scotch to enhance the flavor depth.
5. Continue simmering for another 2-3 minutes to allow the flavors to combine completely. For a chunkier texture, consider adding cranberries in stages so some remain whole while others break down.
6. Remove the sauce from the heat once it reaches the desired consistency. Let it cool to room temperature.
7. Transfer the cooled sauce to an airtight container, then refrigerate until ready to serve. The sauce can be stored in the refrigerator for up to 10 days or frozen for up to two months. When chilled, the flavors deepen further, creating an even more delicious sauce.