Preheat the oven to 350 °F Spray a 9-inch deep pie dish with cooking spray. Place the chocolate sandwich cookies in a food processor and pulse until finely ground.
Add in the melted butter and pulse until moistened. Press the mixture into the bottom and up the sides of the prepared pie dish. Bake for 10 minutes, or until fragrant and set.
Chop the bittersweet chocolate and melt it in a microwave-safe bowl for 30-second increments, stirring between each increment or in a double boiler. Once melted, remove from the heat and let cool.
In a small saucepan, whisk together the granulated sugar and eggs. Set over medium-low heat and cook, whisking constantly, until the mixture reaches 160 °F and coats the back of a metal spoon.