3-D rainbow cake with glitter fondant how to and rainbow how not to

My cousins baby turned one. Michelle's order went something like this "her birthday is on St. Patrick's Day so I want it springy and St. Patricksy, but not TOO St. Patricksy." I thought of this St. Patrick's day cake and started thinking about how I could tweak it to be "not TOO St. Patricksy". Here's what I came up with. The cake with a matching smash cake. So, the crack in the rainbow... my husband did that (bless his soul). He wanted to know how hard the rainbow had gotten so he pinched it... babe, it's not metal in your garage, it's gumpaste in my kitchen. He felt bad, but we rolled with it. Note, do not squeeze your rainbow to test its hardness. :) A general tip, I love, I mean L.O.V.E my matt. I got it at Orson Gygi's and it's right up there with my pizza cutter. I will not make a fondant cake with out it. Just dump a little powder sugar on it (a little bit goes a long way). And spread it around into a very thin layer. If you don't spread it in a THIN layer then the fondant, after you flip it over on to the cake, will have a visible white film of sugar on it. I didn't call attention to it yet, but I decided to play around and discovered how to make my fondant glittery (take a closer look at the finished pictures). I took these glittery color flakes to match the color of fondant I was using (found at cake supply stores and craft stores) and after I spread my sugar out (see how thin my layer is? You can barely see it), I sprinkled the glitter flakes all over my matt. Then I rolled my fondant out on it, hoping it would stick into my fondant. Guess what? It worked! How sad is it that I was bouncing up and down and giggling over my new found glitter fondant? I used gumpaste for my rainbow. I can get away with being lazy and using fondant for smaller things, or bulkier things that will settle on itself andhold itself up, but the rainbow needed to firm up. I mixed up my gumpaste (found in cake supply stores and craft stores in powder form), rolled it out and cut out my rainbow shape. I debated between coloring the fondant and piecing it together or making one solid shape and painting on the colors. I decided the less pieces I needed to hold together the better it would be so I settled on painting. I really think this was a good idea. I used some wooden skewers and then also added some toothpicks to hold the rainbow on the cake. When I used gumpaste on this cake I put it in a warm oven (it was off, but still warm) to harden the gumpaste quicker. My oven on this cake had just been on so I switched it off and threw the rainbow in to it to harden while the it cooled. This would be a how NOT to. The oven was still WAY too hot and after only a few minutes my rainbow had puffed up like a baking sugar cookie. I quickly pulled it out. It was a little misshapen, but I could work with it still. If you want to harden gumpaste fully you should make your piece days in advance. That's the only way to do it. Or keep your oven no hotter than 200 degrees, though that will just harden the outside enough to use it, the middle will still be soft. (As we discovered when my man pinched the rainbow. *smoosh*, nope, the middle is definitely not hard. Thanks for checking that out for me). I painted the colors on, added the clouds and flowers. This has become one of my favorite cakes. I love it!