Add cake mix to a large mixing bowl. Using a mixer, add in your oil, egg whites, and soda, and mix on medium until well incorporated. Mix in the jello.
Add batter into the muffin tin until each is about 2/3 full. Bake for 18-20 minutes, or until a toothpick comes out clean. Allow to cool completely before frosting.
In a large mixing bowl, cream the butter, and cream cheese, and beat until light and fluffy. Mix in the vanilla extract and salt, and then mix the half and half or milk and Shirley Temple soda then mix in the remaining jello.
Slowly mix in the powdered sugar, while adding a bit of the liquid mixture. Continue to mix for 1-2 minutes or until creamy and forms stiff peaks. Add in food coloring if desired.
Fill a piping bag and pipe on the frosting and finish with a cute straw and sprinkles.
Serve and enjoy.