Preparation Steps

• If your pie crust is not prebaked, preheat oven to 350°F (175°C). Blind-bake the crust for 10 minutes, then cool. If using a prebaked crust, set it aside.
• In a medium bowl, whisk together sugar, cocoa powder, cornstarch, and salt until evenly combined.
• In a saucepan, warm the milk over medium heat until it just begins to steam (do not boil).
• Gradually whisk about 1 cup of the warm milk into the dry cocoa mixture to make a smooth paste, then return that mixture to the saucepan with the remaining milk, whisking constantly.
• Cook over medium heat, whisking continuously, until the mixture thickens and comes to a gentle boil, about 3 to 5 minutes. Continue to simmer for 1 minute while whisking.
• In a small bowl, whisk the egg yolks. Slowly temper the yolks by whisking in a few tablespoons of the hot chocolate mixture, then pour the tempered yolks back into the saucepan, whisking constantly.
• Cook for another 1 to 2 minutes, stirring constantly, until the filling is thick and glossy. Remove from heat and stir in the butter and vanilla until smooth.
• Pour the hot filling into the cooled pie crust, smoothing the top. Press a piece of plastic wrap directly onto the surface of the filling to prevent a skin from forming and let cool to room temperature.
• Chill the pie in the refrigerator for at least 2 hours (or until set). Before serving, top with whipped cream and sprinkle chocolate shavings over the top.