1. Prepare pudding as directed with 1 1/2 cups milk. Remove from heat and cover. Refrigerate until cool, then stir in bananas.
2. Cut cake in 3 layers. Place on layer on serving plate. Spread about 1 1/2 cups pudding over layer. Top with second piece of cake. Spread remaining filling. Top with remaining cake.
3. Beat cream and sugar until stiff peaks form, spread on top and sides of cake.
4. Shortly before serving add sliced banana over cake.