Dump Truck Cake Decorating Idea for Boys

I made this dump truck cake for a 2-year-old boy’s birthday. His mom requested for a road transportation-themed cake with 3D vehicles on it. She did not want too big a cake as the birthday celebration was among very close family members only and so we agreed to make it a single-tier cake.

As for the exact design of the cake, she was not very picky about it. She left it to me to design the cake, so long as there were 3D vehicles on the cake and the theme centered around vehicles. So I designed a dump truck birthday cake with a dump truck as the main topper and made 2 additional 3D vehicles on the sides of the cake. And this was how the completed dump truck birthday cake looked like:

A square cake with a dump truck cake topper. Cake is decorated with scenery on the sides and a fondant car and bus on the cake board.

Dump Truck cake for a 2 year old boy's birthday

Decorating the cake was not difficult. I did a dump truck, a car and a bus in 3D and the rest of the decoration on the cake centered around 2 different scenery – the city as well as hilly countryside. And most of these decorations were formed with fondant so I would say decorating this cake was pretty easy and basic.

Let’s look into the details of how I decorated this dump truck birthday cake below.

How to Make a Dump Truck Cake

Main supplies for the cake:

Cake – This was a 7 inches square cake. I baked it using my chocolate cake recipe. The cake consisted of 2 layers and once completed, was approximately 4 inches high.
Chocolate Ganache – I used chocolate ganache as the filling for this cake.
Buttercream – Buttercream was merely to crumb coat the cake. I used chocolate buttercream for this project.
Fondant – I used Satin Ice for this project in quite a number of colors. The readymade colors I used were yellow, black, green, red, orange, blue, white and baby blue.
CMC – Since I used fondant to make the 3D vehicles on the cake, I had to add CMC to it so that it would set firm and hard.
Gum paste – This was used for the lettering (both on the plaque as well as the dump truck).
Chocolate pebbles – These are pebbles looking tiny chocolates in crunchy sugar shells. I purchased these from a local cake decorating supplies shop.
Scalloped round cutter set – I used this for the tree on the side of the cake.
Plunger cutters – I used squares, circles and 5-petal flower shapes.
Pizza cutter and s u gar craft knife
Plaque cutter – This was used to hold the “Happy Birthday” wording on the cake.
Alphabet cutters – I used Tappit block letters cutter for the “Happy Birthday” and the birthday boy’s name. I also used a large number cutter for the number “2”, which I purchased locally.
Wooden Skewer – This was to hold the plaque on the cake.
Lollipop sticks – This was the traffic lights pole.
Food color – Americolor Navy Blue , Wilton Juniper Green , Wilton Brown .
Fondant shaping tools
Fondant glue and shortening.

Decorating the dump truck birthday cake

I stared by getting all the 3D vehicle toppers on the cake ready. Here's how I made them:

Dump truck cake topper filled with stone-like candies on a birthday cake

3D Dump Truck Cake Topper

Coloring the fondant

I used navy blue (white mixed with Americolor Navy Blue color) for the main body of the lorry, Satin Ice yellow for the container and Satin Ice black and red for the wheels, windscreen and the wheel rims. And then I kneaded some CMC into all these colors.
The CMC was to help the fondant set hard and firm. Another option if you do not want to use CMC is to use gum paste. But using gum paste for me meant that I would have had to mix all the colors individually. This is time consuming. Fondant had readily available pre-mixed colors, so I went ahead with the CMC.

The base of the dump truck

To make the lorry, I started with main part i.e. the base of the dump truck which is the long navy-blue piece of fondant that runs from the front to the end of the lorry.
To make the base, I rolled a thick piece of navy blue block and shaped it into a long rectangle. And then I cut another smaller piece of rectangle in about the same thickness and attached it (with glue) to one end of the earlier base rectangle. This was the engine section of the lorry.
Next to it, I cut a thicker piece of square, rounded the edges with my fingers and attached it in an upright standing position. This was the driver seat section.
For the container, I used yellow. I rolled and cut out a long thick rectangle (length was not longer than the remaining base of the dump truck after being taken up by the engine and seating sections of the truck).
And then I used my tools to scoop out some fondant from the top of the yellow rectangle piece and smoothed the interior. I placed this container on a cake board and left it aside to set.

The wheels

Next were the wheels. I used my round cutter for the 4 wheels in thick black fondant and added red rims to each. I left these to set and harden completely, overnight. The next day, when all the dump truck parts are completely set, I assembled the dump truck. I used glue to attach the container and the wheels to the truck.
For added support, underneath the base of the dump truck (where its hidden by the wheels, I placed additional pieces of navy blue fondant to support the base. And then I added the chocolate pebbles into the container.
Finally, I added the rest of the remaining smaller parts of the dump truck such as the lights, mudguard for the wheels, front grill, windscreen and windows to complete the 3D dump truck topper.

3D Car Topper

I hand shaped this car in red (with CMC added). Once I had the shape of a car, I used my shaping tools, and marked lines for the doors and windscreen. And then I used my round plunger cutter to cut out holes at the base of the car to insert its wheels.
Using the same cutters, I made the car wheels in black. I let these wheels dry and set completely overnight before attaching them to the car with glue. And then I added the rest of the car parts such as the windows, windscreen, lights, front grills, etc to complete the 3D car.

3D Bus Topper

The bus was made in orange and I shaped it by hand. To start, I rolled my orange fondant that has been added CMC into a fat sausage. From there, I shaped it into a bus, and added the wheels, windows, lights, front grill, etc to complete it.

3D Traffic Light

This was very easy to make. I cut out a thick piece of black rectangle block and then attached 3 circles in red, yellow and green to denote the colors of the traffic light. And then I inserted a lollipop stick (that has been dipped in glue first) into the block. I left the traffic light to set and firm up in a horizontal position until it was ready to be put on the cake.

Fondant Plaque

This is the plaque that held the ‘Happy Birthday’ lettering on the cake. I cut this plaque out in red ( with CMC added). In fact, I had 2 same sized pieces attached together with a wooden skewer in between.
For the lettering, I used my Tappit alphabet cutters for the words “Happy Birthday” in white gum paste that has been rolled very thin. I attached these letters to the plaque with shortening. The plaque was also left to dry and set in a horizontal position until it was ready to be put up on the cake.

A square cake with a dump truck cake topper. Cake is decorated with scenery on the sides and a fondant car on the cake board.

Dump Truck Cake with 3D Dump Truck Topper

Assembling The Cake

Baking the cakes

To assemble this dump truck birthday cake, once both layers of the cake have baked and cooled down, I leveled and sandwiched them with ganache. And then I crumb coated the cake with chocolate buttercream.

Covering the cake

Next I covered the whole cake in Satin Ice baby blue fondant. I placed the cake on a cake board and covered the sides of the board in black. I wanted the cake board to look like road, so I added white divider lines on the cake board, all around the cake.

The scenery on the sides of the cake

Before adding all the 3D decorations on the cake, I completed the scenery around the cake first. For the city scenery, I used grey, blue and black for the various blocks of buildings. There were no special cutters used for these, I only used my pizza cutter and a ruler. For the small square windows on the buildings, I used my square plunger cutter.
For the hilly countryside scenery, I used 4 different shades of green , 2 for the hills (Wilton Juniper green in dark and light shades), and 2 for the tree (Satin Ice green). The hills were cut free hand. And so was the tree trunk. I created a slightly marbled effect for the tree trunk by mixing brown and white fondant together.
As for the leaves on the tree, I used my round scalloped cutter set for the multiple layers of leaves. The last layer, i.e. the smallest cut out was made using my 5 petals flower plunger cutter. And I added 2 small red balls on the tree as fruits.
The sun was cut out using a round cutter while the rays were cut using my pizza cutter. And so was the brown fence at the corner. The tiny orange and white flowers with red and yellow centers were cut out with a 5 petal flower plunger cutter and the centers were merely tiny balls of fondant attached with shortening.
All these were attached to the cake with shortening.

Adding the 3D vehicles

Once the sides of the cake were completed, I added the 3D decorations. I placed the dump truck topper on the cake, right in the center. And then I poked the ‘Happy Birthday” message into the container. I also added the 3D number “2” in green and attached to a toothpick. And then I added the birthday boy’s name on the dump truck.
Finally, I placed the remaining two 3D vehicles onto the cake, both on the cake board. To secure them in place, I applied a little glue to the wheels for all 3 vehicles.
And that was how I decorated this dump truck birthday cake.

Hope this was useful.

Happy Decorating 🙂