In a medium saucepan whisk together the sugar, milk, cornstarch, salt, and lightly beaten egg yolk
Cook over medium heat, whisking frequently. Cook until the mixture begins to bubble and starts to thicken about 10-12 minutes. Don't turn up the heat to make it cook faster, you want the pudding to cook slowly to avoid burning the mixture.
Remove from heat and whisk in butter and vanilla paste.
Place broken-up pieces of graham crackers sliced bananas on the bottom of a small casserole dish.
Pour the pudding over the bananas and graham crackers, and top with more slices of banana.
Sprinkle finely crushed graham crackers on top.
Cover with plastic wrap and refrigerate until set and serve cold.
Notes
Choose the Right Bananas: Just like with banana bread, the choice of bananas can make a big difference. However, in contrast to banana bread, where overripe bananas are preferred, for banana pudding, you want to use bananas that are ripe but still firm, to prevent them from turning mushy.Make Homemade Custard: The custard is the backbone of banana pudding. It does make a difference in terms of flavor and richness. Use fresh ingredients for the best result.Layering Is Key: The arrangement of your ingredients can affect the final result. Always start and finish with a layer of graham crackers, with bananas and custard in between. This will allow the graham crackers to absorb some moisture and become deliciously soft.Use Plain Graham Crackers: The cookies play a substantial role in banana pudding, so opt for a plain graham crackers to avoid an oeverly sweet taste. For a more traditional banana pudding, substitute vanilla wafers for the graham crackers. Let It Sit: Banana pudding gets better with time. Allowing it to sit in the fridge for a few hours, or even overnight, lets the flavors meld together and enhances the overall taste.Top with Fresh Whipped Cream: Instead of store-bought, try making your own whipped cream for topping. It's simple to make and the freshness will enhance the taste of your pudding. Serve Chilled: Banana pudding is best served chilled. Before serving, make sure it has had enough time in the refrigerator.