Dark magic! This luxurious pie makes its own chocolate-sugar topping as it bakes. Based on an old Southern favorite, chess pie, its texture hits the sweet spot between cheesecake and custard. A dollop of chocolate-infused whipped cream (see "tips," below) takes it over the top.
To make the crust: Stir together the flour, sugar, and salt.
Work the butter into the dry ingredients (using your fingers, a pastry blender or fork, or a mixer) until the dough is unevenly crumbly.
Dissolve the espresso powder in 1 tablespoon of the milk. Sprinkle up to 5 tablespoons (or more, if necessary) of the milk into the dry ingredients (beginning with the tablespoon of espresso milk), continuing to mix until the dough is cohesive. Grab a handful; if it holds together willingly, and doesn't seem at all dry or crumbly, you've added enough liquid.
Shape the dough into a disk. Roll its edges along a floured work surface (as though the disk were a wheel), in order to smooth them out. Pat the disk until it's about 1" thick, wrap it in plastic wrap, and refrigerate for at least 1 hour, or overnight.
Preheat the oven to 350°F. Remove the dough from the refrigerator. Allow it to warm a bit and become flexible, 15 to 30 minutes
Flour your work surface, and roll the dough into a 12" circle. Transfer the dough to a regular (not deep dish) 9" pie pan that's at least 1 1/4" deep. Trim and crimp the edges. Place the crust in the refrigerator to chill, while you're preparing the filling.
To make the filling: Beat together the butter, sugar, and salt until smooth.
Add the eggs one at a time, beating slowly but thoroughly after each addition; you want to combine them with the butter and sugar, but not beat in a lot of air.
Stir in the cocoa, liqueur, milk, and vanilla.
Use a food processor (mini, if you have one) to grind together the espresso powder, cornmeal, and chocolate chips. Add to the batter. Pour the batter into the crust.
Bake the pie for 45 minutes, adding a crust shield after 20 minutes. The middle may look pretty soft; so long as the temperature has reached 165°F right in the center, the pie is done. Note: If you're baking in a stoneware or glass pan, the baking time will almost certainly be a bit longer. Go by how the pie looks, not by your timer.
Remove the pie from the oven, cool to room temperature, then cover and refrigerate overnight before serving.
Serve each slice topped with a layer of whipped cream and a sprinkle of chocolate curls, if desired.
