01 - Rinse cranberries thoroughly and discard any soft or damaged berries.
02 - In a medium saucepan over medium heat, combine sugar, orange juice, water, orange zest if using, ground cinnamon, and salt. Stir until sugar is fully dissolved.
03 - Add cranberries to the saucepan and bring the mixture to a rolling boil.
04 - Reduce heat to low and simmer, stirring occasionally, until most cranberries have burst and sauce has thickened, approximately 10 to 12 minutes.
05 - Remove from heat and allow to cool to room temperature; the sauce will thicken further as it cools.
06 - Transfer to a serving bowl or airtight container and refrigerate until serving.