In a mixing bowl, combine 1 ½ cups all-purpose flour and a pinch of kosher salt. Cut in ½ cup unsalted butter until the mixture resembles coarse crumbs. Gradually add 3 to 4 tablespoons of ice water, mixing until a dough forms. Shape into a disc, wrap in plastic, and refrigerate for at least 1 hour to chill and firm up.

Preheat your oven to 375°F (190°C). On a lightly floured surface, roll out the chilled pastry to fit your 9-inch pie plate. Carefully transfer the crust to the plate, trimming any excess. Prick the bottom with a fork, then line with parchment paper and fill with pie weights. Bake for 20 minutes until lightly golden, then remove the weights and let it cool.

In a large mixing bowl, whisk together 1 cup apple butter, 3 large eggs, and ¾ cup dark brown sugar until smooth. Add 2 tablespoons of all-purpose flour and 1 teaspoon of vanilla extract, mixing until fully incorporated. Gradually blend in 1 can (14 ounces) of sweetened condensed milk, ensuring the filling is creamy and well-combined.

Pour the apple butter filling into the cooled pie crust, smoothing the top with a spatula. Bake in the preheated oven at 325°F (163°C) for 40-45 minutes, or until the center is set but slightly jiggly.

Once baked, carefully remove the pie from the oven and let it cool on a wire rack for approximately 3 hours.

While the pie cools, whip 1 cup of heavy cream with 2 tablespoons of powdered sugar, ½ teaspoon of vanilla extract, and 1 teaspoon of ground cinnamon in a chilled bowl. Beat until soft peaks form.

Once the pie has cooled, slice it with a sharp knife. Serve each slice topped with a generous dollop of your freshly made cinnamon whipped cream.