In a medium saucepan, pour 3 cups of fresh apple cider and bring it to a boil over medium-high heat. Reduce the heat and allow the cider to simmer for 30-45 minutes, stirring occasionally, until it reduces to approximately 1/3 cup. The cider should be thicker and more concentrated in flavor. Remove from heat and let it cool to room temperature.

While the cider cools, preheat your oven to 350°F (175°C). Prepare for the next steps by gathering all your ingredients and equipment.

In a food processor, blend 1 ½ cups of digestive cookies or graham crackers until they turn into fine crumbs. In a bowl, mix the crumbs with ½ cup of melted unsalted butter, 2 tablespoons of powdered sugar, and a pinch of salt until combined. Press this mixture firmly into the bottom of an 8-inch springform pan and bake for 10 minutes, or until lightly golden. Allow to cool completely.

In a stand mixer, add 16 ounces of room-temperature cream cheese and blend until smooth. Gradually incorporate ½ cup of brown sugar, mixing until there are no lumps. Add in 1 cup of sour cream, 1 teaspoon of vanilla extract, and 1 teaspoon of cinnamon, blending until well combined. Slowly pour in the cooled reduced apple cider, mixing just until everything is blended together smoothly.

Add 3 large eggs, one at a time, to the cream cheese mixture while mixing at low speed. Finally, sprinkle in 2 tablespoons of all-purpose flour, and mix gently until combined. Avoid overmixing.

Pour the filling over the cooled crust in the springform pan. For a water bath, place the pan inside a larger roasting dish filled with hot water, ensuring the water reaches halfway up the sides of the pan. Bake in the preheated oven for 80-90 minutes. The edges should be set, but the center will still jiggle slightly when done.

Once baked, turn off the oven and crack the door open. Let the cheesecake cool in the oven for 30 minutes. Afterward, transfer it to the counter to cool completely before wrapping and refrigerating it for at least 8 hours, or overnight.