One of the best ways to demonstrate a fun theme at a kid's birthday party is with the cake. Get creative and use icing, candy, or cookies to decorate sheet cakes or cakes cut into a shape. A great cake can be the centerpiece of your table and is sure to impress your guests.

Molded cake pans

Cake pans are available in a wide variety of sizes and shapes. Most of the popular children's characters are available as cake pans as well as more generic designs so it is possible to match nearly any party theme with a molded cake pan. Some of the most popular pans for toddlers include Blue's Clues, Winnie the Pooh and Elmo. Older children may enjoy superheroes such as Spiderman, princesses such as Cinderella or Jasmine or other favorites like characters from Dora the Explorer. Cars, trains, teddy bears, flowers, sports balls, dinosaurs and zoo animals are all quite popular with kids as well.

Three-dimensional cake pans make upright molded cakes in a variety of shapes. They are not really any more difficult to use than an ordinary cake pan and the unique design you end up with is more than worth the small amount of extra labor. These cakes are so innovative, they are sure to wow your guests. Note that you will need to use a really dense type of cake in order for it to properly hold the shape. Pound cake is ideal and moist pudding cakes also work well.

Cut cakes into shapes

Regular flat sheet, square or round cakes can be cut and arranged to create fun shapes without special pans. The easiest way to do this is to first cut a pattern out of waxed or parchment paper. First, trace the pan onto the paper so you make sure to use the maximum amount of cake. Then, sketch and cut until you have the pieces you need. If you are not comfortable drawing freehand, try printing clip art for inspiration. Dense cakes such as pound cake or cakes with pudding in them are easiest to work with for cutting. You can build nearly anything this way, but a few suggestions include:

Fish, shark and dolphin: A rectangular cake can easily be cut into any of these underwater animals. Use extra cake pieces to make "bubbles" iced in white or blue that can float on the cake tray around your marine animal.

Rocket ship: Turn a rectangular cake into a rocket for your little explorer. You can cut a rocket in one piece by simply trimming cake off around the sides. Use mini marshmallows for a cloud of "smoke" at the base for lift off.

Racetrack: Place two round cakes side by side to form a racetrack. Use frosting or licorice whips to make a figure-8 shaped track on the top. Set clean toy cars on the track or make cars from wafer cookies and icing.

Flower pot: Have a gardener in the family? Use two round cakes to make this flower pot. Make two round cakes: frost the bottom layer. Cut a circle of cake from the top layer and remove it. Place the remaining cake "ring" on the top layer. Frost the outside of the "pot" with a pretty pastel icing and fill the inside with "dirt" made from crushed chocolate cookies. Poke lollipops into the dirt for a completed flower pot. For boys or outdoor adventurers, consider supplementing the flowers with gummy worms and bugs.

Flower cake: This is perfect for the budding florist in the house. Bake a single layer of a round cake. Use the remaining batter to make cupcakes. Place the baked round cake on the center of a cake board or baking sheet; this is the center of your flower. Next, peel the paper cups off of the cupcakes and place them around the center as petals. Ice the cake and cupcakes in a uniform color, then add candy or other icing to highlight the center of the flower. For example, you can ice the whole flower in yellow and place chocolate chips in the center to make a sunflower. Use green icing or sour lime jelled candy wedges to make "leaves" around the flower.

Castle cake: Does your little prince or princess want a cake fit for a king? Bake two square cake layers. Once both layers are cool, trim approximately 1-1/2 inches around each side of one of the layers to make a smaller square. Frost the large layer first, then place the smaller layer on top, centered. Frost the smaller layer, too, smoothing the transition between the layers. Place sugar-cone style ice cream cones on the four corners of the castle to make "turrets." Frost them to match the rest of the cake. Use decorating icing to make windows, a door and parapets on the castle. You can also make a drawbridge using frosted graham crackers and licorice whips.

Aquarium cake: Have a fish lover in your home? This aquarium cake is super easy to make. Bake a rectangular cake, or purchase an unfrosted half sheet cake from your local bakery. Frost the entire cake with medium blue icing. Purchase candy rocks and seashells (you can use moldable chocolate to make your own shells) to place along the bottom of the cake. Then, place gummy fish on the cake's surface.

Doll cakes

Start by baking a Bundt cake. (Some people use a metal mixing bowl to bake the cake instead.) Once it is completely cool, place a clean doll into the center of the cake. You can use some icing in the center to help hold her in place. Then, cover the cake in pastel icing by piping rosettes all over it. Frost the bodice of the doll in the same way so she matches. You may add contrasting icing, sprinkles or dragees for extra decoration.