When you are baking a cake for someone who drives or who enjoys trucks, consider creating a cake shaped like a truck. It might seem daunting to make a cake that is shaped like a vehicle, but a truck has a pretty basic shape. You can make it easily by cutting shapes out of sheet cakes and putting them together to assemble the cake. Use candies and frosting to create your truck cake's details.
Place your rectangular sheet cake inside the refrigerator for about half an hour. This practice will help the cake become really cold so that it will be easier to cut and it will not crumble.
Cut the rectangular cake in half horizontally so that it is long and thin. Use your serrated knife so that the cake is less likely to crumble. This part of the cake will serve as the main body of the truck.
Hold one of your chocolate doughnuts next to the cake. Cut two half-moon shapes out of the base half of the cake. These half moon shapes will serve as the wheel wells for your truck cake; they should be large enough for the chocolate doughnuts to fit inside.
Place your long, thin section of the cake onto the cake platter. Place the chocolate doughnuts on the platter just below the base of the truck, fitting them inside the two wheel wells.
Cut another shape from the remaining half of the rectangular sheet cake that will serve as the cab of the truck. This shape should be roughly shaped like a square, but should be slightly larger at the bottom than it is at the top so that it resembles a truck's cab.
Place the cab shape of the truck onto the cake platter flush with the truck base, about a third of the way down from the front. The wider part of the cab should be flush with the other cake section, with the narrower part at the top.
Frost the cake with frosting in the colour of your choice. Use frosting to help the borders between the two cake sections look seamless.
Place black liquorice onto the cake to create details, such as the door, the window and the door handle. Cut the black liquorice ropes to size if you necessary.
Fill the window in with white icing so that it looks like glass.