In a large saucepan, cook cider over medium heat until reduced to ¼ cup, stirring often. For me, this took 8 to 10 minutes. Once reduced, stir in your remaining ingredients, and bring to a boil, stirring constantly for 2 additional minutes.
Remove from heat and cool completely - the sauce will thicken as it cools. Keep refrigerated for up to one week. You may reheat sauce in the microwave on high for 10 to 15 seconds, or until just warm.
Recipe by Kitchen Meets Girl at https://kitchenmeetsgirl.com/apple-cider-caramel-sauce/