Bittersweet chocolate and Dutch-process cocoa meld with a shot of fresh brewed coffee to give an ultra-rich flavor to this creamy French silk pie. A frothy meringue is the secret to lightening the brown sugar-sweetened filling.
- Preheat oven to 325°F. Coat a 9-inch deep-dish pie pan with cooking spray.
- To prepare crust: Combine chocolate wafers and dates in a food processor; process until finely chopped. Add water and oil and process until moistened. Press into the bottom and sides of the prepared pan.
- Bake until crisp, about 10 minutes. Cool completely on a wire rack.
- To prepare filling and garnish: Combine coffee and water in a small bowl. Sprinkle gelatin on top and set aside to soften.
- Whisk egg, milk, 3 tablespoons brown sugar and cocoa in a small saucepan until smooth. Cook over low heat, whisking constantly, until thickened and an instant-read thermometer registers 160°F, 5 to 7 minutes. Do not let the mixture come to a simmer. Remove from the heat. Add the reserved gelatin mixture; stir until dissolved. Add chocolate and vanilla, stirring until melted. Set aside to cool to room temperature, about 30 minutes.
- Beat reconstituted egg whites and cream of tartar in a large bowl with an electric mixer on low speed until frothy. Increase speed to high and beat until soft peaks form. Gradually add the remaining 5 tablespoons brown sugar, beating until the meringue is smooth and glossy.
- Whisk one-fourth of the meringue into the cooled chocolate mixture until smooth. Scrape the chocolate mixture into the remaining meringue and fold in with a whisk. Spoon the filling into the crust and chill, uncovered, until set, about 3 hours.