Bring ¾ cup apple cider, ½ cup pure maple syrup, ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt, and one 2"-long cinnamon stick (if using) to a boil in a medium saucepan.
Add one (12-oz.) bag fresh or frozen cranberries (3–4 cups) to pan and return mixture to a boil.
Reduce heat to medium and simmer, stirring occasionally, until cranberries are falling apart and look glossy and sauce thickens, 8–10 minutes.
Let cool.
Remove cinnamon stick from cranberry sauce; discard.
Transfer to a small bowl.
Serve room temperature, or cover and chill until cold, at least 2 hours.
Do Ahead: Cranberry sauce can be made 2 weeks ahead. Transfer to an airtight container; cover and chill, or freeze up to 3 months. If frozen, thaw in refrigerator overnight before serving.
