Banana Pudding

Line bottom and sides of 2 1/2-quart glass bowl with about 40 wafers. Combine sugar, cornstarch and salt in medium saucepan. Gradually stir in evaporated milk to dissolve cornstarch. Whisk in egg yolks. Add butter. Cook over medium heat, stirring constantly, until the mixture begins to thicken. Reduce heat to low; bring to a simmer and cook for 1 minute, stirring constantly. Remove from heat. Stir in vanilla extract. Let cool slightly. Pour half of pudding over wafers. Top with half of bananas. Layer remaining vanilla wafers over bananas. Top with remaining pudding and bananas. Spoon remaining pudding over exposed bananas. Refrigerate for at least 4 hours. Top with whipped topping.