Preheat oven to 350F (175C).
Place wafer cookies in the basin of a food processor and pulse until mixture is nothing but crumbs.
Add brown sugar and pulse until combined.
Add crumbs to melted butter (in a medium/large bowl) and stir until mixture is evenly combined and crumbs are moistened.
Transfer crumbs to a 9 ½” pie plate and use the clean bottom of a measuring cup to tamp crumbs into the bottom and up the sides of the pie plate to form the crust.
Transfer to 350F (175C) oven and bake for 13 minutes. Prepare your banana cream pie filling while your pie crust cools completely.
Whisk together sugar, cornstarch, and salt in a medium-sized, heavy duty saucepan until combined.
Add egg yolks, milk, and heavy cream and whisk until all ingredients are combined.
Place saucepan over medium heat and use a whisk to stir constantly until the mixture comes to a simmer/begins to bubble (this can take 10 minutes or so, do not crank the heat above medium or you can ruin your filling).
Once simmering, continue to whisk constantly and allow to bubble for 1 minute. Once 1 minute has passed, immediately remove from heat and add butter, 1 Tbsp at a time, whisking until melted and combined after each addition.
Whisk in vanilla extract.
Pour banana cream pie filling through a fine mesh strainer into a large heatproof bowl. Cover surface with plastic wrap (make sure the plastic wrap is covering the surface of the pudding to prevent a skin from forming) and allow to cool for 20 minutes.
Once cooled, pour half of pudding mixture into your prepared pie crust and spread evenly.
Slice 2 bananas and dip each slice in lemon or lime juice. Gently pat dry and place bananas in an even layer over the first layer of pudding. Top banana slices with remaining pudding and smooth with spatula.
Cover the surface of the pie with plastic wrap and transfer to refrigerator. Chill at least several hours.
Once you are ready to serve (or several hour before serving), prepare whipped cream. Combine heavy cream, powdered sugar, and vanilla extract in a large bowl (preferably a metal bowl that you’ve chilled in the refrigerator or freezer for 10 minutes) and use an electric mixer to beat until stiff peaks form.
Dollop or pipe whipped cream over chilled pie and slice and serve. Enjoy!