To prepare the crust, dice the butter, then place it in the freezer while you prepare the other ingredients. In the bowl of a food processor fitted with a steel blade (or a medium mixing bowl), place the all purpose flour, whole wheat flour, sugar, and salt, then pulse a few times to combine. (If not using a food processor, stir the ingredients together in a medium bowl). Add the butter pieces, then pulse just until the dough resembles a cobblestone street. Some pieces will be the size of peas. (Without a food processor work the butter into the dry ingredients with a fork or pastry blender.)
Dissolve the espresso powder in 1 tablespoon of the half and half. Sprinkle over the crust mixture. Sprinkle on whiskey. Add up to 3 tablespoons (or more, if necessary) of the half-and-half to the dry ingredients, pulsing a little after each. Add only as much half and half as you need to for the dough to just hold together when you take a handful.
On a lightly floured work surface, pat the dough into an even, flat, 1-inch disk, wrap in plastic, then refrigerate for 1 hour or overnight.
Once the dough is properly chilled, place a rack in the center of the oven and preheat the oven to 350 degrees F. Remove the pie dough from the refrigerator and allow it to warm at room temperature until it becomes flexible enough to roll, 15 to 30 minutes. On a lightly floured work surface, roll the dough into a 12-inch circle. Transfer the dough to a regular (not deep-dish) 9" pie pan that's at least 1 ¼ inches deep. Trim and crimp the edges, then place the crust in the freezer to chill, while you prepare the filling.
In the bowl of a standing mixer or a medium mixing bowl, 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 ensure the eggs are well combined, without beating in a lot of air. Stir in the cocoa, whiskey, half and half, and vanilla.
In a food processor (mini is easier), grind together the espresso powder, cornmeal, and chocolate. Gently stir it into the batter, then pour the batter into the prepared crust.
Bake the pie for 45 minutes, adding a crust shield after 20 minutes (if you do not have a reusable crust shield, carefully fit the edges with pieces of tin foil). The middle will look very soft. The pie is done baking when the internal temperature has reached 165 degrees F. Remove the pie from the oven, cool to room temperature, then cover and refrigerate overnight before serving.
Serve each slice topped with whipped cream, if desired.
TO STORE: Brownie pie may be stored at room temperature for 2-3 hours. Otherwise, it should be stored in the refrigerator. Wrapped tightly with plastic, brownie pie may be chilled for up to 4 days. Let come to room temperature or microwave for several seconds before serving.
TO FREEZE: Brownie pie may be kept in the freezer, wrapped tightly in plastic and heavy-duty foil for up to 2 months. Defrost overnight in the refrigerator before serving.