In a 9-inch pie plate, mix together cookie crumbs, salt and sugar. Pour melted butter over the top.
Mix together ingredients and press against sides and bottom of pie plate to form a crust.
Bake for 8 minutes and then set aside to cool completely.
Filling
In a saucepan, mix together sugar, salt and cornstarch.
Add a Tablespoon or two of cold milk and stir to combine. Add milk a bit more at a time, stirring to avoid getting lumps.
Cook over medium low heat, stirring frequently until it starts to steam. Drop heat to low and stir in chopped chocolate until melted. Turn off heat while getting the egg ready.
In a small bowl, gently beat egg. Add about 1/4 cup of warm chocolate mixture, stirring quickly to temper. Then add egg and chocolate mixture back to the pan with remaining chocolate mixture, stirring briskly.
Cook over low heat, stirring constantly, until the mixture thickens a bit and then cool completely.
Once the chocolate mixture is cooled completely to room temperature, or even slightly chilled, it’s time to whip the cream.
In a bowl, beat cream until stiff peaks form. Add in the vanilla and cooled chocolate mixture, folding until combined. Spoon into cooled pie crust.
Freeze for at least 4 hours to set.
Serving
When ready to serve, whip the remaining cream, sugar and vanilla until stiff peaks form.
Dollop on the pie and sprinkle with remaining chopped candies if desired.