Preparation Steps

• In a medium bowl, whisk together the granulated sugar and cornstarch until evenly combined; set aside.
• Heat the milk in a saucepan over medium heat until it begins to steam and small bubbles form around the edges (do not boil).
• In a separate bowl, whisk the egg yolks. Gradually whisk about 1/2 cup of the hot milk into the yolks to temper them, then slowly whisk the yolk mixture back into the saucepan with the remaining milk.
• Add the sugar and cornstarch mixture to the saucepan and cook over medium heat, whisking constantly, until the mixture thickens to a pudding-like consistency, about 3 to 5 minutes.
• Remove the custard from the heat and stir in the butter and vanilla extract until the butter is melted and smooth. Let the custard cool for 10 minutes, stirring occasionally.
• Layer a shallow trifle dish or 9x13 pan: start with a single layer of vanilla wafers, then a layer of sliced bananas, followed by a layer of warm custard. Repeat until ingredients are used, finishing with custard on top.
• Beat the heavy cream with the powdered sugar until soft peaks form and spread the whipped cream over the top of the assembled pudding.
• Chill the assembled pudding in the refrigerator at least 2 hours (preferably overnight) to let the flavors meld and the wafers soften slightly before serving.