Well, I was excited. My first challenging shape cake. I had no idea where to start, so I basically just decided to jump in. But I have to admit that I was pretty darn happy with how it turned out. So, here is how you can make a Mario Brothers cake, but you can really use these ideas to make whatever shape cake you would like.
First I figured out what shape pan I should be using to give me the best area to work with. I decided to use two circle pans for the bubble mushroom top and a 9x13 pan for the stump (I did a double layered cake, which is why I used so much. If you are doing a single layer 2 circle pans or one 9x13 pan will be fine). While they were baking I took a piece of computer paper and started to sketch out the image of the Mario mushroom, trying to keep it to the size that would fit on the cake.
When the cake is done and cooled, take your image and see if it will fit well on it. Don't worry if the image is too big or too small, simply sketch over it and re-size it. Cut the image out when you have the new correct size and lay it on the cake. With the image on the cake, take a knife and cut around the image.
Once you have all the pieces cut out, go ahead and place them in the freezer to get them a bit frozen. Getting them frozen will make it easier to frost them with out ripping the cake up and getting crumbs in the icing. Once they are a little frozen, put a nice thin layer of frosting around them and place them back in the freezer. When that frosting is frozen a little, finish frosting them completely. Now you can finish decorating the cake.
The mushrooms come in mainly solid red and medium green, but also blue in the newer games. Remember to leave the spots on the mushroom white and color the rest of the top in with the color you chose. I made the mistake of messing that up. I accidentally colored the spots and left the top white. So, hopefully I won't make that mistake again.
So, if you have a child into video games this might be a fun idea for a birthday cake. What I also wanted to do was make really cute matching cupcakes. How cute would THAT have been!? But if you aren't wanting a Mario cake then this idea really is usable for many other shape cakes... sooooo HAPPY BAKING!