Peel and slice the apples about ½-inch thick. Place the apples in a slow cooker.
In a large glass measuring cup, combine apple cider, syrup/brown sugar, cornstarch, cinnamon, and ¼ cup of water.
Pour the cider mixture over the apples. Cover and cook on low for 2-3 hours. Give the apples a stir every hour. The longer you cook them the softer they'll get.
Stove-top:
Peel and slice the apples about ¼-inch thick. Place the apples in a large saucepan.
In a large glass measuring cup, combine apple cider, syrup/brown sugar, cornstarch, cinnamon, and ¾ cup of water.
Pour the cider mixture over the apples. Bring to a simmer over medium-low heat, and cook, covered, for about 20 minutes, stirring every 5 minutes. If the apples look like they need more liquid you can add a splash of water, apple juice, or apple cider as needed during the cook time. Once the apples are almost completely tender, let them simmer with the cover off for about 5 minutes. The juices will thicken a bit as they cool.
Video
Notes
*You'll want to use baking apples for this recipe. I do not suggest using Granny Smith apples, they are too tart. I recommend Honeycrisp, Pink Lady, Fuji, or Rome apples.If you'd like to keep the skins on the apples, you can. My taste testers preferred these apples without the skin. The skin will help the apple slices hold their shape better.