McKenzie, your little guy might surprise you and if he hasn't been exposed to a lot of sugary foods up until now, he may not be all that interested in the birthday cake. That's what happened to my dd for her 1st b-day last year. We work really hard to keep refined sugar and flour out of her diet. I found a cake that I considered a healthy compromise for her birthday, and she didn't like the icing, took a couple bites of cake and then asked for more peas. She did me proud (and freaked out my MIL!
the recipe I used (Her b-day is in Nov. so it was ideal). Rather than using 2 c AP flour, I used 1 c AP and 1 c whole weat. I also eliminated the nuts on top and just put on some fun colorful sprinkles.
If you haven't already, check out a book called Super Baby Foods
. It has a couple cake and frosting recipes as well as a recipe for a 1st b-day cake.
Keep up the great work!