My oldest turns 5 this week! I can't believe how quickly time flies. He want a "Boy Castle Cake". It thought I would share what I came up. I am in no way a cake decorator, but I know some basics and I loved it when my mom decorated my birthday cake when I was growing up.
I used a 9x13 pan for the bottom layer, a loaf pan for the next layer, the top layer is a stacking block, and I used ice cream sugar cones for the towers. I was going to use cake for the third layer on top but it was leaning and looked awful so I found a toy to substitute.