In a large mixing bowl, combine all-purpose flour, granulated sugar, and kosher salt. Cut in the cold unsalted butter until mixture resembles coarse crumbs. Gradually add ice water, stirring until a dough forms. Shape into a disk, wrap in plastic, and chill for at least 1 hour.

Once chilled, lightly flour your countertop and roll out the dough into a 14-inch round, about 1/8 inch thick. Transfer the rolled dough to a 9-inch pie pan, gently press it in, crimp the edges, and refrigerate again for about 30 minutes.

Preheat your oven to 375°F. Line the chilled crust with parchment paper and fill it with weights. Bake for 25-30 minutes until edges are golden brown. Remove weights and let cool.

In a mixing bowl, whisk melted butter, granulated sugar, and flour until smooth. Add kosher salt, vanilla extract, honey, and eggs one at a time, mixing well. Stir in sour cream and apple cider vinegar until combined.

Pour the filling into the pre-baked crust and bake at 350°F for 45-50 minutes until edges are golden and the center jiggles slightly. Shield edges with foil if needed.

Once baked, cool on a wire rack for at least 2 hours. Sprinkle flaky sea salt over the top before serving.