Heat oven to 375°F. Bake biscuits as directed on bag.
Meanwhile, in 10-inch skillet, melt butter over medium heat. Add brown sugar; beat with whisk until melted and well blended. Beat in water until smooth. Remove from heat. Cover; set aside until biscuits are baked.
To serve, add banana slices to sauce; cook about 2 minutes or until bananas are tender. Split each warm biscuit; place on individual serving plate. Spoon bananas with sauce onto bottom halves of biscuits. Top with whipped topping. Cover with top halves of biscuits. Drizzle with extra sauce.