In a bowl, stir together Splenda Sweetener and cornstarch.
In a saucepan, whisk together milk, egg substitute, vanilla extract, and salt. Add sweetener mixture and whisk to combine, then add butter. Cook over medium-low heat for 4–5 minutes, whisking constantly, until mixture begins to thicken and bubble. Remove from heat. Whisk in banana flavoring.
Transfer pudding to a bowl. Spray a piece of plastic wrap with cooking spray and cover the bowl, gently pressing wrap directly onto the pudding. Refrigerate at least 2 hours before serving.
To serve, divide pudding among 6 bowls and top with sliced bananas.