Preheat your oven to 350°F (175°C).
Combine the graham cracker crumbs, melted unsalted butter, and ¼ cup granulated sugar in a bowl. Press the mixture into the bottom of a pie pan to form a crust.
In a saucepan, melt the semi sweet chocolate over low heat until smooth, then allow it to cool to room temperature.
In a separate bowl, whisk together the whole milk, ¾ cup granulated sugar, egg yolks, and cornstarch until smooth.
Gradually add the melted chocolate to the milk mixture, stirring well to combine. Pour this filling into the prepared crust.
Bake in the preheated oven for 25-30 minutes or until set. Let it cool completely before serving.
Serve with whipped cream on top, if desired.