We used this recipe for gluten-free carrot cake, which we did as cupcakes instead of a cake. We were trying to create this but decided to try to do it just with cupcakes. The brown ones are supposed to be dirt that he's crawling on top of since we did some chocolate cupcakes along with the carrot ones. My MIL helped us with assembling this especially the swirling of the frosting on the cupcakes to create the not a solid color look to them.
Here is our table spread for "appetizers" and the cupcakes. We did all the five foods that the caterpillar eats during his day for the "appetizers". Probably would have been better to have them sliced to make them easier to eat. These weren't that huge of a hit with our guests but I think they look cute. The little circles have what he ate each day. We used a themed table cloth, napkins and plates from Target. For dinner we had baked ziti and sausages.