Slice 1 1/2 of the bananas and arrange in bottom of pie shell.
Pour cold milk into a medium bowl. Add pudding mix. With an electric mixer beat on lowest speed for 2 minutes. Gently fold in 1/2 cup of the whipped topping; mix until well blended. Pour into pie shell.
Place in freezer and freeze at least 2 hours before serving. Allow to thaw slightly before cutting slices.
Garnish with slices of the remaining banana and whipped topping if desired.