1.Place a layer of Nilla Wafers in the bottom of a medium sized mixing bowl. Slice a banana over the top. Repeat two more times with another layer of wafers and remaining bananas. In sauce pot (or double boiler) on medium low heat, add all ingredients except for vanilla. Stir well with wire whisk. Allow to cook, stirring constantly to prevent scorching, until thickened - about fifteen minutes. Add in vanilla and stir. Immediately pour over wafers and bananas. Let sit for about five minutes or so before serving, to allow wafers time to absorb pudding. Top with meringue, if desired.