In a medium mixing bowl, whisk together the sweetened condensed milk and cold water until fully combined and smooth. Sprinkle the instant vanilla pudding mix over the milk mixture and whisk well for 1–2 minutes, until no dry spots remain and it starts to thicken slightly.
1 can (14 oz) sweetened condensed milk, 1 1/2 cups cold water, 1 box (3.4 oz) instant vanilla pudding mix
Cover the bowl with plastic wrap and refrigerate for at least 1–2 hours, or until very thick and completely chilled.
In a large, cold mixing bowl, add the heavy whipping cream. Using a hand mixer or stand mixer with the whisk attachment, beat on medium-high speed until soft peaks form. Add the vanilla extract, then continue beating just until medium-stiff peaks form. Do not overbeat.
3 cups heavy whipping cream, 1-2 teaspoons pure vanilla extract
Remove the chilled pudding base from the refrigerator and gently loosen it with a whisk if very firm. Using a spatula, fold the whipped cream into the pudding in 2–3 additions, cutting down and lifting up gently to keep the mixture light and airy.
Just before assembling, peel and slice the bananas into 1/4-inch rounds. If desired, you may very lightly toss them with a small amount of lemon juice to slow browning, but use only a tiny amount so the flavor doesn’t stand out.
4-5 medium ripe bananas
In a large glass trifle dish, a 9x13-inch dish, or individual cups, place a layer of vanilla wafers on the bottom. Small gaps are fine.
1 box (11–12 oz) vanilla wafers
Add a generous layer of banana slices over the wafers. Spoon about one-third of the pudding-cream mixture over the bananas and spread into an even layer, making sure the bananas are fully covered.
4-5 medium ripe bananas
Repeat the layers—vanilla wafers, bananas, pudding mixture—until you have used all of the components, aiming for at least two full layers and up to three, depending on your dish. Finish with a layer of the pudding mixture on top.
1 box (3.4 oz) instant vanilla pudding mix, 3 cups heavy whipping cream, 1-2 teaspoons pure vanilla extract, 1 box (11–12 oz) vanilla wafers, 4-5 medium ripe bananas
Sprinkle the top with crushed vanilla wafers and, if desired, a light dusting of ground cinnamon or nutmeg. Add shaved white chocolate or a drizzle of caramel for a fancier presentation, if you like.
extra vanilla wafers, ground cinnamon or nutmeg, shaved white chocolate or caramel sauce
Cover the dish tightly with plastic wrap and refrigerate for at least 4 hours, and preferably 6–8 hours or overnight, until the wafers have softened and the dessert is fully chilled. Serve cold straight from the refrigerator.