In a medium saucepan, combine the sugar, flour, and sea salt. Gradually whisk in the milk, ensuring there are no lumps. Place the saucepan over medium heat and cook the mixture, stirring constantly until it thickens and bubbles. This should take about 10 minutes.
In a separate bowl, whisk the egg yolks until they are smooth. Once the pudding base is thickened, slowly add about a cup of the hot mixture to the egg yolks, whisking constantly.
Pour the tempered egg yolk mixture back into the saucepan with the remaining pudding. Continue to cook on medium heat, stirring for an additional 2-3 minutes until it is thick and creamy. Remove from heat and stir in the vanilla extract.
In a clean bowl, beat the egg whites until stiff peaks form. Gently fold the whipped egg whites into the pudding mixture.
In your baking dish or serving bowl, place a layer of vanilla wafers at the bottom. Follow this with a layer of sliced bananas, then pour some of the pudding over the top. Repeat the layers until all the ingredients are used, finishing with a layer of pudding on top.
Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight for best results. Just before serving, top with a generous dollop of freshly whipped cream.
