Place a medium saucepan over medium heat. Stir together the granulated sugar, fresh orange juice, and water. Bring the mixture to a gentle boil, stirring occasionally to ensure the sugar dissolves completely. Adding a pinch of salt at this stage helps to enhance the fruit flavors later on.

Add the rinsed cranberries and the cinnamon stick to the boiling liquid. Reduce the heat to medium-low and let the mixture simmer for about 10 to 12 minutes. You will hear the cranberries begin to “pop” as they burst open. Stir occasionally and cook until the sauce starts to thicken and the berries have reached your desired consistency.

Remove the saucepan from the heat. Carefully fish out and discard the cinnamon stick. Stir in the Grand Marnier and the fresh orange zest. Adding the liqueur at the end preserves its distinct flavor and aroma. Let the sauce cool completely at room temperature; it will continue to thicken significantly as it cools.

Transfer the cooled cranberry sauce into a decorative glass bowl or a ceramic ramekin. Garnish with an extra sprinkle of orange zest or a few sugared cranberries for a festive touch. Serve chilled or at room temperature alongside your favorite holiday proteins.