Mix flour and 1 1/2 cups sugar in saucepan. Combine beaten egg yolks and milk and mix well. Add to flour mixture and blend well. Cook over medium heat and add 1 tea. vanilla. Cook, stirring constantly, until thickened. Place a layer of vanilla wafers in bottom of casserole dish. Add a layer of sliced bananas over wafers. Top with cooked custard mixture. Repeat layers as needed. Beat egg whites lightly, gradually add 1/4 cup sugar. Beat until stiff. Add 1 tea. vanilla. Spread merengue on top of pudding. Bake at 425 degrees until golden brown.