In a medium saucepan whisk to combine cornstarch, Sweet N Low®, and salt. Whisk in just enough milk to make a smooth paste, then whisk in remaining milk and mashed banana. Cook pudding over medium heat, stirring constantly, until it comes to a simmer, then cook 1 minute more or until thickened. Take off heat and stir in vanilla. Transfer pudding to a bowl, press plastic wrap directly on the surface, and refrigerate until chilled, at least 4 hours. In a medium bowl beat cream and SweetN Low® with a hand mixer until softly whipped. In a separate bowl beat chilled pudding until smooth and creamy. To assemble, have ready 7 small jars or glasses. Place ¼ cup pudding in bottom, then top with 2 wafer cookies and a layer of sliced bananas. Top with ¼ cup more pudding, 2 more cookies, and another layer of bananas. Top each with about 1 tablespoon whipped cream. Serve immediately or refrigerate, covered, up to 4 hours.
