CRUST: MIX base cake, nuts and butter. Press 3 cups (1 lb. 2 oz.) firmly onto bottom and 1 inch up side of each of 3 (10-inch) springform pans (or 1 pan for trial recipe). Bake 350°F-standard oven for 12 min. Cool.
FILLING: POUR whipping cream into large bowl. Add dry pudding mix. Beat with wire whisk until well blended. Gently fold in whipped topping.
SLICE 2 bananas evenly over each crust; drizzle each with 1/3 cup of the caramel topping. Spread 4 cups filling evenly over caramel layer; sprinkle evenly with 2 cups of the OREO Pieces. Repeat layers of bananas, caramel and filling. (Filling will come to top of pan.)
GANACHE: MICROWAVE chocolate in large microwaveable bowl on HIGH 1-1/2 min. or until almost melted; stir until completely melted. Cool slightly. Stir in whipping cream with wire whisk until well blended.
SPREAD 1 cup ganache evenly over each torte. Refrigerate 8 hours or overnight. Before serving, garnish torte with dollops of additional whipped topping and mint sprigs, if desired.