Adding Jello to a cake mix can have several benefits. First and foremost, it can add a burst of flavor to an otherwise plain cake. For example, adding strawberry Jello to a white cake mix can give the cake a pink hue and a fruity flavor. Jello can also make the cake more moist and tender. This is because the gelatin in the Jello helps to retain moisture, resulting in a cake that is less likely to dry out.