For a fully baked crust, place dough-lined pie plate in the refrigerator to chill until firm, about 40 minutes. Transfer tart pan to the freezer until very cold, about 20 minutes. Preheat your oven to 375° F. Remove pie plate from the freezer and prick the bottom with a fork. Double line it with aluminum foil and place an even layer of pie weights on top. Bake 35 to 40 minutes or until dark golden in color.

In a large saucepan set over medium heat, whisk together the heavy cream, milk, sugar, cornstarch, and salt. Cook until the mixture is thickened, stirring frequently to prevent scorching. It should be thick enough to coat the back of a spoon.

Place the egg yolks in a small mixing bowl and beat them slightly. When the milk mixture is thick, slowly whisk about ¼ cup of it into the egg yolks until well combined. Whisk the mixture back into the saucepan.

Continue to cook over medium heat stirring constantly, for 2-3 minutes, until thickened. Again, it should cover the back of a spoon with a thick coating. If it's not thick, continue cooking up to 10 minutes.

Remove the saucepan from the heat and whisk in the butter and vanilla. Transfer the mixture to a large mixing bowl and press a piece of plastic wrap to the top of it, then allow it to cool until it's nearly room temperature.

Fold the sliced bananas into the custard, then pour the filling into the pie shell.

Return the plastic wrap to the surface of the pie, then chill in the refrigerator for at least 4 hours or ideally overnight, until cooled and fully set. When ready to serve, top the pie with whipped cream, as desired.