Instructions

• Follow the package instructions to blind-bake the 19-inch refrigerated pie crust. Let the crust cool completely on a wire rack.
• In a medium saucepan, heat the 2 cups whole milk over medium heat, stirring often, until it comes to a boil. Remove from the heat and set aside.
• While the milk heats, whisk together the 6 large egg yolks, ½ cup brown sugar, ⅓ cup sifted cornstarch, ½ teaspoon ground cinnamon, 1/5 teaspoon freshly grated nutmeg, and 1/8 teaspoon kosher salt in a separate large saucepan or heatproof bowl until the mixture is smooth and slightly thickened.
• Temper the yolks: with the yolk mixture whisking constantly, drizzle in ¼ cup of the hot milk. Continue whisking and slowly add the remaining hot milk until fully combined.
• Place the pan with the tempered mixture over medium heat. Whisk constantly while bringing it to a boil. Once it reaches a boil, continue whisking and boil for 1–2 minutes, making sure to scrape and cook at the edges so the mixture thickens evenly.
• Remove the pan from the heat, whisk in 1 teaspoon pure vanilla extract, then let the custard sit undisturbed for 5 minutes. After 5 minutes, whisk in the 3 tablespoons unsalted butter (added in pieces) until the custard is smooth and the butter is fully incorporated.
• Cover the surface of the custard with plastic wrap sprayed with nonstick spray (place the sprayed side directly on the custard to prevent a skin). Refrigerate until the custard is cold, about 1 hour.
• When the custard and crust are fully cooled, peel the 3 bananas and cut them into ¼-inch-thick diagonal slices.
• Whisk the cold custard briefly to loosen it. Spread about 1/4 of the custard in a thin layer over the bottom of the cooled pie crust. Arrange half of the banana slices in a single layer on top of that custard layer.
• Spread half of the remaining custard over the banana layer. Arrange the remaining banana slices on top of that custard. Spread the remaining custard evenly over the top so the bananas are fully covered.
• In a stand mixer fitted with the whisk attachment, beat the 1 cup heavy cream, 2 tablespoons powdered sugar, and 1 teaspoon pure vanilla extract until stiff peaks form. Add the 2 tablespoons sour cream and whisk just until it is incorporated (only a couple of seconds).
• Spread or pipe the whipped cream mixture over the top of the pie. If desired, garnish with a few freshly cut banana slices just before serving. Refrigerate the finished pie until ready to serve.