Whisk together 1 C. milk and corn starch in a small mixing bowl until smooth.

In a 3 ½-quart saucepan combine sugar, salt and remaining ½ C. milk. Cook over low heat, stirring frequently until sugar is dissolved. Whisk in corn starch mixture. Cook over medium heat until mixture thickens, about 5 to 7 minutes.

Whisk ½ C. corn starch mixture into egg yolks in a large mixing bowl. Whisk this back into the mixture in the saucepan and cook over medium-low heat 5 minutes, or until mixture is thickened further.

Remove from heat and whisk in semi sweet chocolate chips. Transfer to prebaked pie crust. Place plastic wrap directly onto filling. Let stand 1 hour; then refrigerate for 6 hours or overnight.

Whip the heavy cream until it forms soft peaks. Add powdered sugar and espresso powder. Whip until medium firm peaks form.

Spread whipped cream on top of pie and garnish with grated chocolate.