Grind 2 cups whole cranberries. Combine with 1 large banana, diced (1 cup), and 1/2 cup sugar. Set aside. Combine 2 cups vanilla wafer crumbs or graham cracker crumbs and 6 tablespoons butter (melted). Press half of the crumb mixture into the bottom of a 9 x 9 x 2 inch pan. Cream 1/2 cup butter, 1 cup sugar until light add 2 eggs and beat until fluffy. Fold in 1/2 cup chopped nuts and spread over layer. Top with cranberry mixture. Whip 1 cup whipping cream until it forms soft peaks. Spread over cranberries. Sprinkle with remaining crumbs. Press lightly. Chill 6 hours or overnight.