Combine graham cracker crumbs, melted butter and sugar; press into the bottom and 1-inch up the sides of a 9-inch springform pan. Bake at 375° F for 7 to 10 minutes. Cool.
Combine pudding mix and sour cream; fold in whipped topping. Spoon half of mixture onto cooled crust. Layer sliced bananas over mixture; top with remaining cream mixture. Sprinkle top with walnuts. Chill for several hours before serving.Makes 10 to 12