Preheat oven to 375°F. Coat the bottom and sides of a 9" pie plate with cooking spray or softened butter.

Graham Cracker Crust: Reserve 1 tablespoon crumbs for topping. Combine the remaining crumbs, sugar, cinnamon, and 1/8 teaspoon salt in a bowl, stirring well. Stir in egg white and butter. Press crumb mixture into bottom and up the sides of the 9-inch prepared pie plate. Bake at 375° for 9 minutes or until lightly toasted; cool completely on a wire rack.

Chocolate Cream Filling: Combine the sugar and the next 6 ingredients (through egg yolk) in a bowl, stirring well with a whisk. Place the milk in a medium, heavy saucepan over medium-high heat; cook until milk reaches 180° or until tiny bubbles form around edge (do not boil). Gradually add the hot milk to the egg mixture, stirring constantly with a whisk. Return the combined mixture to the pan; cook over medium heat 10 minutes or until thick and bubbly, stirring constantly. Remove from heat. Add the chocolate pieces; stir until smooth.

Transfer the chocolate filling back to the large mixing bowl and place the bowl in a larger ice-filled bowl or pan to hasten the chilling process. After about ten minutes and a few stirs here and there, the filling can finally be spooned into the prepared graham cracker crust. Cover the surface of filling with plastic wrap. Chill for 3 hours or until set; remove plastic wrap.

Whipped Cream Topping: Using a hand mixer or a stand mixer fitted with a whisk attachment, whip the heavy cream, sugar, and vanilla extract on medium-high speed until medium peaks form, about 3-4 minutes. Spread whipped topping over pie; sprinkle with the reserved cracker crumbs. Keep chilled until ready to serve.