At least 2 hours ahead, make the pie dough: Make the pie crust through step 5 according to my directions and video tutorial in my pie crust recipe. Make pie dough in advance because it needs to chill in the refrigerator for at least 2 hours before rolling out (step 2).

Roll out the chilled pie dough: On a floured work surface, roll out one of the discs of chilled dough. Turn the dough about a quarter turn after every few rolls until you have a circle 12 inches in diameter. Carefully place the dough into a 9-inch pie dish. Tuck it in with your fingers, making sure it is completely smooth.

Chill the pie dough in the refrigerator for at least 30 minutes and up to 5 days. Cover the pie crust with plastic wrap if chilling for longer than 30 minutes.

Preheat oven to 375°F (190°C).

Blind bake the crust: Line the chilled pie crust with parchment paper. Fill with pie weights or dried beans. Bake until edges are starting to brown, about 15–16 minutes. Remove pie from the oven and carefully lift the parchment paper out of the pie.

Prick holes all over the bottom crust with a fork. Brush egg wash on edges if desired for a shiny golden crust. Return pie crust to the oven and bake for 14–15 minutes. Remove from the oven and cool on a wire rack completely before filling.

Make the custard filling: Whisk the egg yolks and cornstarch together. Set aside. Combine the milk, heavy cream, sugar, and salt in a medium saucepan over medium heat. Whisk until sugar has dissolved, then bring to a gentle simmer, whisking occasionally.

Remove about ½ cup (120ml) of the milk mixture and, in a slow stream, whisk into the egg yolk and cornstarch mixture. Pour and whisk the egg yolk mixture into the pot. Cook for 1 full minute, whisking constantly.

Remove the pan from heat and whisk in the vanilla and butter. Allow to cool for 15 minutes. Place plastic wrap directly on top of the warm pudding to prevent a skin from forming.

Slice 2–3 bananas and arrange slices into the cooled pie shell. Spread custard on top. Refrigerate for at least 4 hours and up to 1 day.

Make the whipped cream: Whip the heavy cream, sugar, and vanilla extract until medium peaks form, about 3–4 minutes. Pipe or spread the whipped cream on top. Garnish with banana slices before serving.

Slice and serve. Cover leftovers and store in the refrigerator for up to 5 days.