For your child's birthday, you want to make her dreams come true, and you'll go to any extreme to make the children's novelty cake she requests. Whether she loves Dora the Explorer or SpongeBob SquarePants, you can make her favourite character come to life. You don't have to be an expert baker to make a novelty birthday cake -- you just need to be creative. And though making a theme cake may be time consuming, it will all be worth it.
Bake a cake based on the size of the party you are having. If you're having a large party, you may need a 12 inch by 18 inch sheet cake. If it's a smaller party, you can use a 9 inch by 13 inch baking pan.
Search online for a picture of the novelty character on which your cake is themed. If your party is themed after a movie, you can find this type of picture on the movie's website. Pictures of a cartoon character can be found on the network's website. If you have a colouring book of the character with a picture you like, you can use that as well. Make sure the picture is close to the same size as the cake, but no larger. If the picture is not large enough, resize it before you print it to make it larger. You can do this in the settings on your printer. Cut the picture out, following the lines exactly.
Lay the picture on top of the cake, making sure none of the edges of the picture are hanging over the sides of the cake. Use a toothpick to trace the picture onto the cake. Remove the picture, and use the toothpick to draw in the details of the character. If it helps, gently write the first letter of the colour each section should be to help you stay organised when you are icing the cake.
Cut away the sides of the cake around the edges of the character using a serrated knife. Set the extra cake aside, as you might want to use it to add details or texture later.
Separate the icing into different bowls based on colour, and squeeze a few drops of food colouring into each bowl to colour the icing. Ice the cake according to the colours in your picture. Use an icing bag to draw in the lines, facial features, and other details.
After you frost the cake, you can use another toothpick to draw on the eyes and other details. That way, you will have guidelines when you are using the icing bag. If you don't have an icing bag, put the icing into a plastic baggie and snip off one corner to make your own icing bag.