Makes one 9-in [23-cm] deep-dish pie
NOTE: Piled high with billowy whipped cream or toasted meringue, nothing says 1950s diner dessert quite like chocolate pie. But even 50 years earlier, at the turn of the 20th century, Chocolate Bavarian Cream, essentially chocolate pie filling with the addition of gelatin, was very popular. Here, I have modified a recipe from Knox Gelatin Dessert, Salads, Candies and Frozen Dishes (1936), adding Mexican hot chocolate spices to the filling and topping it with an ancho chili powder-and-black pepper toasted meringue. Marrying spicy and sweet flavors is a decidedly modern trend, and this pie is a perfect example of how well they pair.
1. Preheat the oven to 350°F [180°C]. Grease a 9-in [23-cm] deep-dish pie plate with nonstick cooking spray or softened butter.
2. For the crust: In the bowl of a food processor fitted with the metal blade, process the wafers, sugar, cinnamon, and salt until combined. Add the melted butter and pulse until combined. Scrape down the bowl of the processor as needed.
3. Transfer the mixture to the prepared pie plate and, using your hands, press the mixture into the bottom of the plate and up the sides, creating a uniformly thick crust. Place the pie plate in the freezer for at least 30 minutes or up to 3 days, covered in plastic wrap.
4. Bake for 8 to 10 minutes, rotating at the halfway point, until the crust is lightly browned, fragrant and dry to the touch. Let cool completely.
5. For the filling: Place the chocolate in a large bowl. Pour the milk into a small bowl and sprinkle the gelatin on top. Let it bloom until the gelatin has been absorbed.
6. In a medium saucepan, whisk together the heavy cream, sugar, salt, cinnamon, and cayenne pepper. Place the saucepan over medium-high heat, whisking constantly. Once bubbles form on the surface, remove from the heat, and add the bloomed gelatin and whisk to combine. Pour the mixture over the chocolate and whisk until the chocolate melts. Whisk in the vanilla and pour the filling into the cooled pie shell until it is about 1/2 in [12 mm] below the edge of the crust. If you have extra filling, transfer it to a small bowl and refrigerate along with the pie—it is delicious on its own. Press plastic wrap on the surface of the filling to stop a skin from forming, and refrigerate for at least 4 hours until set, or overnight.
7. For the meringue: In the bowl of a stand mixer fitted with the whisk attachment add the whites, salt, vanilla, cream of tartar, black pepper, and chili powder and whisk together on medium speed until frothy. Add the sugar in a slow and steady stream and continue to whisk on high speed until stiff, glossy peaks form, at least 5 to 7 minutes.
8. If you do not have a kitchen torch, preheat the oven to 350°F [180°C].
9. Spoon the meringue over the chilled pie, making sure the meringue touches the crust’s edges.
10. Use the back of a spoon to make gentle swirls all over the top. Using a kitchen torch, toast the meringue topping. If you do not have a kitchen torch, toast the meringue in the oven for 5 to 10 minutes, watching closely to avoid burning. Refrigerate for at least 2 hours or overnight, lightly covered in plastic wrap, and serve.
11. The pie is best served the day it is made, but will keep in the refrigerator, lightly covered in plastic wrap, for up to 3 days.