Make the Pudding: In a medium bowl, whisk together the instant vanilla pudding mix and cold milk. Beat for 2 minutes, or until the pudding thickens. Stir in the vanilla extract and sweetened condensed milk until well combined. Set aside to firm up for 5-10 minutes.

1. Whip the Cream: In a separate bowl, beat the heavy cream and powdered sugar with an electric mixer until stiff peaks form.
2. Combine the Pudding and Whipped Cream: Gently fold the whipped cream into the prepared pudding mixture until smooth and well combined.
3. Assemble the Pudding: In a large serving dish or individual cups, layer vanilla wafer cookies, followed by sliced bananas, and a generous layer of the creamy pudding mixture. Repeat the layers, finishing with a layer of pudding on top.
4. Chill: Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight, to allow the flavors to meld and the wafers to soften.
5. Serve: Garnish with additional vanilla wafer cookies, banana slices, or whipped cream before serving.