In a medium size double boiler combine flour,sugar,salt and beaten eggs.cook over medium heat stirring constantly.Slowly add milk. If you don't have a double boiler you can make one by using a medium pot with about 2 inches of boiling water and use another pot with your ingredients placed on top of boiling water.
Cook until mixture thickens. Remove from heat add vanilla stirring until blended.Let cool.
Line casserole dish with layer of vanilla wafers then top with sliced bananas. Continue with the layers until dish is about 2/3 full. Pour the pudding mixture over the top making sure to seal the edges.
In a small bowl add egg whites.Beat with electric mixer for 2 minutes until soft peaks form. Reduce speed and slowly add sugar and vanilla.Spread the meringue on top of the pudding mixture.Place in preheated oven for about 10 minutes or until lightly brown. Makes about 10 servings