This constructions site cake was done for my son’s 5th birthday, his current interest being big trucks and construction equipment.
I started with a half sheet cake (Wilton 1/2 sheet pan) and baked a half chocolate, half white cake mix.
Using regular white buttercream icing I frosted the entire cake, making some landscape details like holes in the ground out of the icing. After allowing the icing some time to form a slight crust, I then took my decorating brushes to paint the surface with browns, yellows and greens. This can be faster and easier if you own an airbrush, but if not a paintbrush, gel colors, and warm water work well.
After adding the ground color I took cake crumbs that I had dried up in the oven and ground in the food processor, and scattered them about the surface. The borders are iced with chocolate buttercream, the top with some regular white added for contrast. I also added some great “rocks” that were actually chocolate candies found at the local grocery store, shaped like rocks. The crumbs and “rocks” are key. My son was so impressed, he believed they were real rocks and dirt!
Write a greeting and add the trucks/cars/figures of your choice. This surface would work well for a farm, monster trucks, animals, many different scenes, and you could add a lake with colored decorating gel.