Whisk together the flour, sugar, and salt in a large bowl. Add the butter and mix with a pastry blender or fork until the mixture resembles coarse meal and the butter is the size of small peas.

Add 1 tablespoon of water and continue mixing. Add more water as needed, 1 tablespoon at a time, until a dough forms.

Wrap the dough tightly in plastic wrap. Refrigerate for at least 2 hours.

Remove the dough from the refrigerator. If necessary, let it sit at room temperature for 10 to 15 minutes until slightly softened but still cold.

Lightly flour a work surface. Roll out the dough into a circle about 1/8-inch thick.

Transfer the dough to a 9-inch pie plate. Trim and crimp the edges as desired. Place the pie plate in the refrigerator while you make the filling.

Place the butter and chocolate in a microwave-safe bowl. Heat at half power in 30-second increments until the butter has melted and the chocolate melts when stirred. Stir until combined. Allow to cool about 10 minutes.

Add the flour, sugar, brown sugar, Kahlua, vanilla, flour, and salt to the chocolate mixture. Stir until thoroughly combined.

Add the eggs, one at a time, mixing well after each addition.

Transfer the filling to the crust. Bake 50 to 60 minutes, or until the center is set and the top is puffed.

Cool in the pan on a wire rack. The pie will fall as it cools.

Serve warmed, at room temperature, or chilled with sweetened whipped cream or ice cream.