The theme of my son's 4th birthday party was race cars - one of his favourite topics and easy enough to translate into decor, activities, etc. We were determined to have a race-track cake, with these 'specifications': had to feed a lot of people (18 kids, 30+ adults); no fondant icing; no excessive cake "architecture"; use existing cake pans/etc; and have matchbox/hot wheels cars on top as decorations. Cue the most amazing sister-in-law in the world, who pulled out her big cake pan and set to work!
This 4th Birthday Race Track Cake is really simple enough - she used a rectangle cake pan and her favourite cake recipe ( on birthday boy's request, this one was "marble" choc-vanilla) and flavored icing recipe (traditional buttercream recipe to be the best for decorating; easy to spread around, doesn't "melt" too fast when out of the fridge, and can made it as sweet (or not) as desired) (which in this case, was 'not very'; did I mention, 18 kids on a sugar high?).
She baked the rectangle cake and iced as plain and smooth as possible, using a very large icing spreader. Then she piped the 2 edges of a long "race track" in the shape of a 4, using the same icing. Very carefully, she sprinkled OREO cookie crumbs between the outline, to make the 'blacktop' race track. Was tricky not to spill the crumbs outside the track; a less steady hand might want to lightly drape waxed or parchment paper over the non-track area (or just touch up the icing when finished with crumbs).
Then, 'dashes' of white icing were piped as lane dividers. Added 2 matchbox cars as 'racers'. I'd found construction pylon candles and 'winners circle' race tape at a party supply store (serendipity!); finished off by making a little "START" banner taped to 2 wooden skewers and little black-and-white checkered flags, glued onto toothpicks. Rest of party decor featured a lot of checkered flags on the walls, race-car themed party plates, car-related loot bags & lots of 'races' and such as activities.