Transfer to a mixing bowl and cover with plastic wrap, making sure no air is present. Once cooled somewhat transfer to the refrigerator to cool for an hour.
Once cooled, spoon half of this pudding mixture into the cooled pie crust.
Slice 3 bananas and lay evenly over the top of the pudding, then spoon the remaining pudding over the top of the bananas.
4 Each Bananas
Cover again with plastic wrap, making sure no air can reach the pudding, then refrigerate for at least 4 hours (overnight if you can).
When you are ready to serve the banana cream pie, add the heavy cream to a mixing bowl and beat with the vanilla and powdered sugar until stiff peaks form.
1 Cup Heavy Whipping Cream, ½ teaspoon Vanilla Extract, 2 Tablespoons Powdered Sugar
Spoon this over the top of the pudding, then top with sliced bananas.
Notes
Once you slice the bananas they will start to blacken. This is why it's best to slice the bananas for the top of the cream pie when you're ready to serve.You could also use orange/lemon/lime to coat the sliced bananas - this will ensure no darkening happens, but it will add a citrus tang though.