1. Heat oven to 350 degrees F. Coat a 9-inch round cake pan with nonstick cooking spray.
2. In a medium-size bowl, whisk together flour, cinnamon and salt. In a large bowl, mash bananas until smooth. Beat in egg, egg whites, Splenda sugar blend, brown sugar and oil, about 2 minutes. Stir in the flour mixture just until blended.
3. Transfer batter to prepared pan. Bake at 350 degrees F for 25 to 30 minutes, or until center springs back when pressed.
4. Cool cake in pan on wire rack for 5 minutes. Invert cake to rack and cool completely.
5. Meanwhile, in a medium-size bowl, beat together light cream cheese, Splenda sugar blend and butter until smooth. Refrigerate until ready to frost.
6. Once cake has cooled, invert cake right side up onto stand or plate. Spread frosting only over top of cake, and sprinkle with trail mix. Makes 12 servings.