Combine the milk and butter in a medium saucepan
over medium-low heat, stirring gently to melt
Mix together 5 tablespoons of sugar
and the cornstarch in a small bowl. Add 2 tablespoons water and mix to create a paste, and then whisk
into the milk
mixture. Raise the heat to medium and cook, stirring, until thick and bubbly, 7 to 10 minutes. Remove from the heat and stir in the vanilla extract.
Transfer to a bowl, cover with plastic wrap
(make sure the plastic is touching the pudding to prevent a skin from forming) and refrigerate for at least 4 hours.
Combine the whipping cream
with the remaining 1 tablespoon sugar in a bowl. Beat with an electric mixer
until stiff peaks form. Set aside.
Create a layer of wafers on the bottom of an 8- by 8-inch dish, and then add a layer of bananas
and a layer of pudding
. Repeat to make a second layers. Top with whipped cream
. Cover and refrigerate for 8 hours or overnight before serving.