Espresso Mud Pie
30 chocolate cookie wafers, such as Nabisco Famous Chocolate Wafers
4 tablespoons unsalted butter (1/2 stick), melted and cooled
4 ounces semisweet chocolate, coarsely chopped
1/2 cup heavy cream
1 tablespoon unsalted butter
1 quart coffee ice cream or gelato
1 cup heavy cream
2 tablespoons granulated sugar
1/2 teaspoon vanilla extract
Place cookies in the bowl of a food processor fitted with a blade attachment and process until the pieces are about the size of peas. Stop the motor, add the melted butter, and continue to process until the crumbs are fine, about the size of coarsely ground coffee (you should have about 1 1/2 cups). Alternatively, place the cookies in a resealable plastic bag, press out the air, and seal. Using a rolling pin, smash into fine crumbs until uniform. Transfer to a medium bowl, add melted butter, and mix until evenly combined.
Pour crumb mixture into a 9-inch pie plate and, using the bottom of a cup or your fingers, press firmly and evenly into the bottom and up the sides. Bake until fragrant, about 10 to 15 minutes. Remove to a wire rack to cool completely before filling.
Place chocolate in a medium heatproof bowl; set aside.
Place cream in a small saucepan over medium heat and bring to a simmer. Pour over chocolate and let stand until chocolate has softened, about 5 minutes.
Add butter and stir until smooth. Let cool slightly before using.
Place gelato in the refrigerator until slightly softened, about 30 minutes. Place cookie crust in the freezer until chilled, about 30 minutes.
Remove softened gelato from the container and transfer to a large bowl. Stir with a rubber spatula or wooden spoon until it is spreadable but not liquidy. Working quickly, spread the softened gelato into the crust in an even layer (leaving any melted gelato in the bowl). If the gelato in the pie looks like it’s melting, place the pie in the freezer until solid before proceeding.
Pour the warm ganache over the gelato and tilt the pie plate to evenly coat. Immediately transfer the pie to a flat surface in the freezer until completely frozen, at least 3 hours.
Let the pie sit at room temperature until the ganache just begins to soften, about 15 minutes. Meanwhile, combine cream, sugar, and vanilla in a large bowl and whisk until soft peaks have formed (they should droop over like soft-serve ice cream), about 3 minutes; serve atop pie slices. If not serving immediately, tightly wrap the frozen pie in plastic wrap and store in the freezer for up to 1 week.