OH SHOOT! The first time I tried this , the jello was way too runny. It soaked through the cake & ran out the bottom. You should have seen me stuffing towels, napkins, & small furry creatures around the edges as a pool of pretty blue liquid was oozing across the counter-top, under the microwave, and down the front of the cabinet onto the floor. Slightly thickened? I tried a second time, & waited until the jello was more than half set, and that worked so much better. That night, as my 6 year old son was getting ready for bed, he told us that decorating that cake was the best part of the day, even better than the water balloon fight he had with his sister!