Mix together 3/4 cup sugar, 2 tablespoons of flour and a pinch of salt. Separate 2 egg yolks from the whites (save the whites for the meringue). Beat egg yolks with 1 cup of milk and combine all ingredients in the top of a double boiler. Cook until thick, stirring constantly. Remove from heat; cool and add 1 teaspoon of vanilla. Line a dish with vanilla wafers (1 box), alternating with a layer of bananas (6 to 8) then more wafers. Pour sauce over all. Beat egg whites for the meringue. Brown in 350 degree oven.