Prepare the crust by baking it according to the package instructions or your recipe, then let it cool completely.

1. For the chocolate filling, combine the heavy cream, milk, and sugar in a saucepan. Heat over medium until it begins to simmer, then remove from heat.
2. Whisk the egg yolks with cornstarch, salt, and a small amount of warm milk mixture. Slowly pour it into the milk mixture, whisking constantly. Return to medium heat, cooking for 5-7 minutes until thickened and bubbling.
3. Remove from heat and stir in chopped chocolate, butter, and vanilla extract until smooth.
4. Pour the chocolate filling into the cooled pie crust, smoothing the top. Let the pie cool at room temperature for 15 minutes, then refrigerate for at least 3 hours until fully set.
5. Once chilled, garnish with whipped cream and chocolate shavings or cocoa powder if desired. Slice and serve!