In a mixing bowl, whisk together egg yolks, sugar, cornstarch, and salt. Gradually stir in milk until well combined.

Cook over medium heat in a large saucepan, stirring constantly, until mixture thickens and comes to a boil. Boil for one minute. Remove from heat and stir in vanilla. Press plastic wrap into custard surface to prevent a skin from forming and refrigerate until chilled, at least two hours.

Meanwhile, place all pie crust ingredients into a bowl and mix until well combined. Press crumb mixture evenly into a 9" pie crust and freeze for 20 minutes.

Place pie crusts on a serving platter and fill with chilled custard.

In a microwave or double boiler set over simmering water, melt chocolate chips, butter, and corn syrup, and stir until smooth. Pour the chocolate glaze over the custard filling, and let the glaze harden.