In a large bowl, whisk together the sweetened condensed milk and ice-cold water until well combined. The cold water is key—it helps the pudding set faster and creates a smoother texture. Add the instant vanilla pudding mix and whisk vigorously for about 2 minutes until fully incorporated and slightly thickened. Set aside and let chill for 5 minutes while you prepare the remaining components.

While the pudding chills, prepare the bananas by slicing them into ½-inch rounds and immediately tossing them with lemon juice to prevent browning—I find that tossing them gently in a bowl works better than coating them after layering, as it ensures even distribution. In a separate large bowl (or in batches if your mixer is small), whip the heavy cream to stiff peaks. This should take about 3-4 minutes with an electric mixer on medium-high speed.

Gently fold the whipped cream into the chilled pudding base using a spatula, being careful not to deflate the cream. Work in two or three additions, folding gently each time until the mixture is light, fluffy, and fully combined. This creates the signature creamy texture of banana pudding for a crowd.

Start building the dessert in a rectangular pan by spreading a thin layer of the pudding mixture on the bottom. Add a layer of vanilla wafers, then a layer of banana slices, then more pudding mixture. Repeat these layers—pudding, wafers, bananas—until all ingredients are used, finishing with a pudding layer on top. I like to reserve some of the nicest banana slices and wafer pieces for the top to make it look beautiful. Ensure even distribution so each serving will have all the components.

Cover the pan with plastic wrap and refrigerate overnight (or at least 6 hours). This resting time allows the flavors to meld and the wafers to soften slightly into the pudding, creating the perfect texture. Just before serving, you can dollop extra whipped cream on top if desired, or serve it on the side.