Preheat oven to 450 degrees F. Line crust with parchment paper and weight it with dried beans ; bake until dough is lightly golden and set, (about 10 to 15 min.) Remove pie and cool. (Preferably on a wire rack)
Lower oven temperature to 350 degrees F.
Filling: In a bowl, stir together butter, sugar, and cocoa until well combined. Fold in flour, eggs, and vanilla and mix until smooth (you can use a electronic or hand mixer). Pour mixture into prepared crust. Bake for 30 to 40 minutes.
Remove pie from oven and cool completely on a wire rack to ensure even cooling. Place ice cream over pie and freeze until ice cream sets (think of it as another layer).
Optional: Drizzle with fudge sauce before serving.