In bowl, whisk together granulated sugar, cornstarch, salt and egg yolks.
In saucepan, heat milk with 1 tablespoon of the espresso powder to just under a simmer, whisk into egg yolk mixture.
Pour back into saucepan; cook, whisking constantly, until thick. Add 4 oz Ghirardelli 100% Unsweetened Chocolate Baking Bar; whisk until chocolate is melted and mixture is smooth.
Pour into crust and press plastic wrap onto surface of filling; refrigerate at least 1 hour or until set.
Just before serving, whisk cream with confectioners’ sugar, 1 tsp Prova Gourmet Madagascar Bourbon Vanilla Extract, and remaining 1/2 teaspoon espresso powder until soft peaks form.
Cut pie into 8 slices; top each slice with a dollop of the whipped cream. (If you prefer, mound the whipped cream on top of the pie and spread it with a spatula before cutting.)