• Preheat the oven to 350°F. Lightly grease a 9x13-inch baking dish.
• Whisk the milk, ½ cup of the sugar, egg yolks, and cornstarch in a saucepan until smooth.
• Cook over medium heat for 7-10 minutes, stirring constantly. The mixture should thicken and begin to bubble.
• Remove from the heat and stir in the butter and vanilla extract until smooth.
• Spread a thin layer of the pudding on the bottom of the prepared dish.
• Add a single layer of vanilla wafers on top of the pudding, followed by a layer of sliced bananas.
• Pour half of the remaining pudding over those layers.
• Repeat with more wafers, bananas, and the remaining pudding, finishing with pudding on top.

Meringue

• Beat the egg whites and cream of tartar with an electric mixer until soft peaks form.
• Gradually add the 3 tablespoons of sugar, beating until stiff, glossy peaks form.
• Gently fold in the vanilla extract.
• Spread the meringue over the warm pudding, spreading it all the way to the edges of the dish to seal it.
• Bake for 10–15 minutes, or until the meringue is lightly golden on top.
• Remove from the oven and let cool at room temperature for about 1 hour, then refrigerate for at least 1–2 hours before serving.