Cakes are usually associated with sweetness, especially among children. Kids love sweet things and that is why they always see a birthday or any special event as the time to enjoy. For your birthday cake, you could choose chocolate cake. Children and adult would love that. You could also prepare cake that is not too sweet in case of adult guests who are not too interested in sweet things or who are diabetic. Having this combination ensures that everyone has a nice time at your birthday party.
The cake theme basically comes down to focusing on what the child is most interested in, so, as a parent, you have the opportunity to be the Cake Hero and provide your youngster with a cake that will make their eyes open wide and smile with delight as they shout out, "Wow! This is really cool!"