Pour 2 cups of apple cider into a medium saucepan over medium heat. Bring to a gentle boil, then reduce and simmer for 10-15 minutes until thickened to about 1/2 cup. Cool completely.

Preheat oven to 325°F. Combine graham cracker crumbs, brown sugar, and melted butter. Press into bottom of springform pan and bake for 12 minutes. Cool.

In a bowl, beat cream cheese with granulated sugar until smooth. Gradually add cooled apple cider, sour cream, and vanilla extract. Mix until no lumps remain.

Add eggs one at a time, mixing on low speed. Sift in flour and cinnamon, mixing just until incorporated.

Wrap springform pan with aluminum foil to prevent leaks. Place in a larger baking dish and prepare a water bath.

Pour cheesecake batter over the crust. Optionally swirl in apple cider mixture or cinnamon sugar. Smooth top.

Pour hot water into the outer pan halfway up the springform pan. Bake for 70-80 minutes until edges are set but center jiggles slightly.

Turn off the oven, crack the door, and cool the cheesecake for 30 minutes. Then, cool to room temperature and refrigerate for at least 6 hours.

Mix melted butter with apple cider. Brush over the cheesecake and sprinkle with cinnamon sugar.