In a medium saucepan, boil 3 cups of fresh apple cider over medium heat, optionally adding mulling spices. Let it simmer for about 20–30 minutes until reduced to approximately ⅓ cup. Allow to cool.

Preheat your oven to 350°F (175°C).

In a food processor, grind 2 cups of digestive cookies into fine crumbs. Mix with 6 tablespoons of melted unsalted butter, ¼ teaspoon of salt, and 2 tablespoons of powdered sugar. Press into a lined 8-inch round cake pan and bake for 10 minutes.

In a large mixing bowl, beat 3 softened bricks of cream cheese with 1 cup of brown sugar until smooth. Gradually mix in 1 cup of sour cream, 2 teaspoons of vanilla extract, ½ teaspoon of salt, and 1 teaspoon of cinnamon. Fold in the cooled reduced apple cider.

Add 2 tablespoons of all-purpose flour and 3 large eggs, mixing on low speed until just combined.

Pour the filling into the cooled crust and bake in a water bath for about 90 minutes, until edges are set but the center jiggles slightly.

Turn off the oven and crack the door ajar, allowing the cheesecake to cool slowly for about 30 minutes. Transfer to a wire rack to cool completely, then refrigerate for at least 8 hours before serving.