To make crust in a medium bowl stir together crushed vanilla wafers and butter until blended. Firmly press on bottom and sides of a 9 inch pie plate.
Bake at 350 for 10-13 minutes or until lightly browned. Remove to a wire rack and let cool 30 minutes or until completely cool.
For the pudding whisk together sugar, flour, eggs, yolks and milk in a heavy saucepan. Cook over medium low heat. Whisking constantly 10-12 minutes or until it reaches the thickness of chilled pudding.
Mixture will just begin to bubble and will be thick enough to hold soft peaks when whisk is lifted. It must be thick and slightly bubbly to set up properly. Remove from heat and stir in vanilla.
Transfer to a medium bowl and cover with plastic wrap making sure to press the plastic directly on top of the custard so it doesn't get a skin on it. Refrigerate until completely cool. Can be made up to a day in advance.
To make whipped cream in a medium bowl whip cream on medium high speed until soft peaks form. Slowly add sugar and vanilla and continue to beat until thick and stiff. Don't over beat.
To assemble arrange half of the banana slices evenly over bottom of cooled crust. Spread 1/3 of cooled pudding over bananas then layer with 20 vanilla wafers.
Spread 1/3 more pudding over vanilla wafers then add the remainder banana slices and cover them with the last of the pudding.
Spread the whipped cream over the entire pie and decorate with more vanilla wafers if desired.
The layers from bottom up should be vanilla wafer crust, bananas, pudding, vanilla wafers, pudding, bananas, pudding, whipped cream. Refrigerate at least 4 hours or overnight.