I currently make cakes at a grocery store and my husband's work is doing a cake competition for his work to raise money for the special Olympics. I have never mad a larger cake other then a three tiered round cake. I am not that experienced in fondant but can practice to use it. Do you have any ideas for a beginner cake maker.

3D cakes are always a hit. You don't have to cover them in anything except buttercream if you want. If you have a 3D ducky pan, you can easily turn it into a horse by rounding off the tail end, extend muzzle with buttercream, add fondant ears, jr mint eyes, and add tail and mane and forelock using long pulls of buttercream.

Just as a suggestion on the 3d cakes theme, the owl cake in my photos was really quite easy, it was 3 round cakes, I trimmed the edges and used these trimmings to make the rounded part on top of the head and carved it into a slightly owl like shape, then I buttercreamed it and wrapped my fondant around it. there was no need for neatness because I was sticking on lots of feathers so if you aren't very experienced with fondant that might be good. for the feathers all I did was roll out some fondant, and start cutting, once I got bored I stuck some on, then started cutting again.

Edit: I forgot to mention I used a small leaf cutter out of a set I had, you could probably pick one up cheap if you don't already have one, I'm actually glad I got to use mine as I bought a whole set for flower making, but I'm too scared to try it lol

Hat box or gift box cakes LOOK like they are REALLY hard, but they aren't.... you can use butter cream OR fondant.... I have a couple in my photos if you care to look for ideas.....

Brainstorming ...... when is the competition?
Is it around a particular holiday? Holidays always make a good theme.
Is in during a specific season? Does your area have brilliant fall colors or heavy snowfalls? You could work those into a theme.
Is it during a sporting event season or is there a popular team in your area? I'm in Alabama so from during September to November anything with football and University of Alabama or Auburn University is a big hit!

Also, if there are any landmarks or other specific things about your town that are well known and recognized people would be impressed if you put it into a cake.

HTH. Be sure to let us know how you do!
Good Luck!

I watched this video a while ago and thought it was a really cute idea. It's a BC 'how to' butterfly cake. It's made with 1, I think 9" round cake: