In a sauce pan, combine butter and cream and bring to a simmer. Pour over chocolate chips in a separate bowl and stir until the chocolate is melted and the mixture is smooth and glossy. Pour ½ of the mixture into the pie shell, spread to make even and set aside. Reserve remaining gananche.

In a heavy-bottomed sauce pan combine the milk with ¼ cup of the sugar and salt. Dissolve the sugar and bring just to a boil.

In a separate bowl whisk together the egg yolks, egg, remaining ¼ cup of sugar, and cornstarch and beat until smooth.

Temper the egg mixture by slowly streaming the hot milk into the egg, stirring constantly until the egg is warm.

Add the egg mixture to the rest of the milk on the heat and continue to cook, stirring constantly until it comes to a boil and thickens. Remove from heat.Stir in vanilla and butter.

Arrange sliced bananas over the cooled ganache and spoon the warm custard over the bananas. Smooth the top of the custard and place in fridge to cool completely.

Top with sweetened whipped cream and a drizzle of the reserved ganache.