Instructions

1. Lightly flour a work surface. Place 1 pie crust on it and roll out to a 12-inch round. Transfer it to a 9-inch pie pan (not deep-dish). Press it into the bottom and up the sides. Trim all but 1 inch of the excess pie dough from around the edge. Fold the edge under itself, then crimp the edges with your fingers or a fork. Using a fork, poke holes all over the bottom of the crust. Refrigerate for at least 30 minutes. Meanwhile, make the pastry cream.
2. Place 1 1/2 cups whole milk, 1/2 cup heavy cream, 1/3 cup granulated sugar, and 1/4 teaspoon kosher salt in a medium saucepan and whisk until the sugar dissolves. Place over medium heat and cook, swirling occasionally, until steaming but not boiling, about 5 minutes. Meanwhile, fit a fine-mesh strainer over a medium bowl. Place 4 large egg yolks and 1/4 cup cornstarch in a second medium heatproof bowl and whisk until smooth.
3. Turn off the heat. Use a measuring cup or ladle to scoop out about 1 cup of the steamed milk. While whisking constantly, slowly pour it into the egg mixture and whisk until combined. Pour the egg mixture into the saucepan with the remaining milk mixture.
4. While whisking continuously, cook over medium heat until the pastry cream just comes to a simmer around the edges and starts to thicken, 1 1/2 to 3 minutes. Remove the saucepan from the heat. Add 2 teaspoons vanilla extract and whisk until combined.
5. Pour the pastry cream into the strainer. Push through the strainer with a flexible spatula; scrape the pastry cream on the underside of the strainer into the bowl. Discard the contents of the strainer. Press a sheet of plastic wrap directly onto the surface of the pastry cream to prevent a skin from forming. Refrigerate until cold, at least 3 hours and up to 2 days. Meanwhile, blind bake the pie dough.
6. Arrange a rack in the lower third of the oven and heat the oven to 425°F. Place the pie dish on a baking sheet. Line the crust with parchment paper or aluminum foil, making sure to completely cover the bottom and sides and pressing it up against the sides. Fill the crust with pie weights.
7. Bake until the edges of the crust start to turn golden-brown, 12 to 15 minutes. Remove the crust from the oven. Grasp the corners of the parchment or foil, and lift the weights out of the pie. Transfer them to a bowl or plate to cool.
8. Return the crust to the oven and bake until the edges are browned and the bottom is lightly golden-brown, 5 to 8 minutes more. Let cool completely, about 1 hour.
9. Peel and slice 2 of the medium bananas crosswise into 1/2-inch rounds. Arrange the slices cut-side down in a single, tight layer in the crust, starting from the outside and working your way in towards the center.
10. Transfer 1/2 cup of the pastry cream (reserve the plastic wrap) onto the bananas and use the back of a spoon or small offset spatula to push the cream into the empty spaces between the slices. Top with the remaining pastry cream and smooth out the top. Press the reserved plastic wrap directly against the surface of the pastry cream. Refrigerate for at least 2 hours or up to overnight.
11. Make the whipped cream:
12. When ready to serve, make the whipped cream: Place 1 1/2 cups cold heavy cream, 1/4 cup powdered sugar, and 1/2 teaspoon vanilla extract in the bowl of a stand mixer (or large bowl if using an electric hand mixer). Beat with the whisk attachment on medium speed until firm peaks form, 4 to 5 minutes.
13. Spoon the whipped cream evenly on top of the pie. Alternatively, pipe the whipped cream: Transfer it to a piping or zip-top bag. Cut off the bottom tip of the piping bag or one bottom corner of the zip-top bag with scissors. Pipe decoratively onto the pie.
14. Peel and slice the remaining 1 medium banana crosswise into 1/2-inch rounds. Garnish the top of the pie with the slices.