Pre-heat oven to 350 degrees. Mix together the cake batter ingredients (above) then cook it according to the directions on the box in a 9x13 inch pan. (About 25-30 min)
When cake is completely cooled after baking, mix together the first jello package with 1 cup boiling water, then stir in 1/2 c. cold water. Jell-o mix needs to remain in liquid form for dispensing so don't refrigerate before adding to cake.
Make a bunch of holes in the cake using the handle end of a butter knife. Using a child's medicine dispenser, add about 1 to 2 tsp of Jello into every other hole. (see picture above)
When finished, repeat steps with the second color of jell-o.
Cover cake and refrigerate until ready to serve (at least 1 hour). Add frosting when cake is cold.
Using a hand mixer, thoroughly blend the frosting ingredients, then spread evenly over the cake.
Optional: just before serving, top with fruit or sprinkles.