Prepare brownie mix according to package directions. Beat whipped topping mix and 1/2 c milk at high speed with an electric mixer for 5 minutes. Transfer topping to a separate bowl and reserve. Do not wash mixer bowl. Add pudding mix and 1 c milk to bowl. Mix on low speed for 2 minutes. Fold whipped topping into pudding, by hand or on very low speed until well mixed. Chill while assembling banana splits. Place a brownie in the bottom of a large bowl. Spread brownie with pineapple topping. Splile a banana in half lengthwise and place it next to the brownie on either side. Place desired amount of banana mousse on top of the brownie. Top with whipped cream, chocolate topping, nuts and a cherry.