Place sugar, salt, corn starch, flour and gelatin in a large pot over high heat and gradually stir in milk.
Bring mixture to a boil and continue to boil for one minute, constantly stirring then remove from heat
In a small bowl slowly ladle mixture into your beaten eggs while whisking until eggs are tempered. (Do this very slowly as you do NOT want to cook your egg yolks before they reach the pot)
Stir your tempered egg mix into the pot and bring back to a boil for one more minute.
Remove from heat and blend in butter and vanilla
Let pudding cool
Stir bananas into pudding
In a bowl or small trifle alternate a layer of pudding and a layer of crushed vanilla wafers until full
Let pudding set in refrigerator for at least 2 hours before enjoying, best served after refrigerated overnight and topped with fresh banana slices.