Nonstick cooking spray
16 ounces chocolate sandwich cookies such as Oreos (35 to 40 cookies), crushed
5 tablespoons unsalted butter, melted
4 tablespoons (1/2 stick) unsalted butter
6 ounces good-quality dark chocolate (60 to 70 percent), chopped
2 tablespoons plus 1 teaspoon instant espresso powder
1/4 cup strong coffee, at room temperature
1/4 teaspoon salt
1 tablespoon pure vanilla extract
6 large eggs, separated, at room temperature
1 cup sugar
3/4 cup sugar
1/2 cup dark unsweetened good-quality cocoa powder
1/4 cup cornstarch
1/4 teaspoon salt
4 large egg yolks
2 1/2 cups whole milk
3 tablespoons unsalted butter
2 teaspoons pure vanilla extract
3 ounces good-quality dark chocolate (60 to 70 percent)
1 1/4 cups heavy cream
2 tablespoons granulated sugar