Mix graham cracker crumbs, sugar, melted butter or margarine, and ginger until well blended . Press mixture into a 9 inch pie plate. Cool in refrigerator.
In a sauce pan, boil an unopened can of sweetened condensed milk for 3 hours. Monitor the water closely, to make sure there is always water in the pan. Remove can from heat and let cool for 10 to 15 minutes.
Open can and pour toffee into pie crust. Allow to cool.
Slice bananas over toffee.
Whip 2 cups of cream and spoon it on top of bananas. Refrigerate before serving.