Make the crust: In a food processor, pulse the Oreos® into fine crumbs. Add the butter and pulse to incorporate. Press the crumbs into the bottom and up the sides of a deep 9-inch pie tin. Keep in the refrigerator while you make the dark chocolate ganache.
Make the dark chocolate ganache: In a medium microwavable bowl, combine all the dark chocolate ganache ingredients. Microwave on high until the chips have melted, 1 to 2 minutes. Then whisk until smooth. Pour into the crust and chill until firm, 1 hour.
Make the milk chocolate ganache: In a medium microwavable bowl, combine all the milk chocolate ganache ingredients. Microwave on high until the chips have melted, 1 to 2 minutes. Then whisk until smooth. Pour over the dark chocolate ganache and chill until firm, 2 hours.
Make the espresso whipped cream: In a large bowl, combine all the whipped cream ingredients. Using an electric hand mixer, beat to stiff peaks. Spread over the chilled milk chocolate ganache. Chill the pie for 1 hour more.
For garnish: In a small bowl, stir together the confectioners' sugar and instant espresso. Remove the pie from the refrigerator and, using a fine-mesh sieve, dust the top with the sugar mixture. Sprinkle with chocolate-covered espresso beans. Then slice and serve.