This Monster Jam Gravedigger cake stole the show at my son’s 2nd birthday party. It’s a classic chocolate layer cake decorated with black, purple, and electric green buttercream and checkered fondant. It’s inspired by Gravedigger’s signature colors. Follow this fun monster truck cake tutorial, where I share all my DIY decorating tips and tricks!

A Gravedigger monster truck cake on a white cake stand.

Monster Jam Birthday Cake Tutorial

IFor months I had been planning my son’s second birthday with a Monster Jam theme. He loves Monster Trucks but has always loved Gravedigger the most. We were lucky enough to go to our first Monster Jam show right before his birthday which made for a pretty special week.

I’m so excited to finally share the details of this Monster Jam Gravedigger cake. It’s a chocolate layer cake decorated with creamy buttercream colored black, purple, and electric green to match Gravedigger’s signature colors, decorated with checkered fondant and topped with his favorite version of the truck.

A Few Details About This Cake

Minimal fondant. After scouring the internet and socials for Monster Jam birthday cake ideas, I found many layer cakes that were heavy on the fondant and sheet cakes similar to my construction cake. I knew I wanted a layer cake, but more buttercream-forward, so I set out to create my own.
Simple technique. This Monster Truck cake design uses basic buttercream decorating techniques and pre-colored fondant. It doesn’t require any piping tips at all, just a few piping bags with the tip cut off.
Easy to customize. You can do this with any version of the truck using any colors for the buttercream to match the theme. The checkered fondant, edible tires and edible rock decoration translate well to any Monster Jam truck. Plus, I am sharing some DIY decorations you can tie into the theme.

Close up of a Gravedigger monster truck cake on a white cake stand.

What You’ll Need

This is a three-layer, 6” chocolate layer cake frosted with buttercream. Although the frosting starts with a vanilla buttercream base, most of the frosting is actually chocolate flavored, thanks to cocoa powder (but more on that later).

I’ve included notes below on what you’ll need to make and decorate this Monster Jam cake. You’ll find the full recipe and instructions in the printable recipe card after the post.

Cake – I use my chocolate cake for the layers in this tutorial, but you can use any flavor of cake you’d like.
Buttercream Frosting – You’ll need a batch of vanilla buttercream, which you’ll color using a combination of cocoa powder and gel food coloring.
Gel Colors – I use purple, electric green, and black gel food dye to match Gravedigger’s signature colors. You can adapt this tutorial with more colors to match your child’s favorite Monster Truck characters.
Fondant – This Monster Truck cake uses black and white rolled fondant to create the checkered flag detail around the bottom edge of the cake. You’ll find ready-made fondant in baking and craft stores or online in small quantities, you don’t need much!
Oreos – Finely crushed to make the “dirt” on top of the finished cake. Any chocolate cookie works.
Decorations – These can be Monster Truck toys (remember to wash them well first!) and any other decorations you’d like to add to your Monster Jam cake. I include detailed decorating tips later on in the tutorial.

A Gravedigger monster truck cake on a white cake stand, surrounded by toy Monster Trucks topped with mini party hats.

How to Make a Monster Jam Gravedigger Cake

First, you’ll need to prepare three 6-inch chocolate cake layers (or the flavor of your choosing). Bake the cake layers until a toothpick stuck into the center of the cakes comes out clean. Afterward, the cakes will need to cool completely before you level the layers, assemble the cake, and create a crumb coat.

If you’re new to making layer cakes, I have a helpful post on how to make a layer cake that goes over the steps in full detail.

Instead of Chocolate Cake, Try These

Yellow Layer Cake

A slice of three-layer frosted red velvet cake on a plate next to a fork.

Red Velvet Layer Cake

Oreo Cookies and Cream Cake

A close up of a slice of a 3 layer vanilla cake on a white plate

Moist Vanilla Layer Cake

If you aren’t a fan of chocolate cake, you can make this Monster Jam cake using my classic vanilla cake recipe or any of the homemade cake recipes from my site, including the ones I suggest here. Of course, if you’re pressed for time, even a boxed cake mix does the trick.

Prepare the Buttercream

My frosting recipes start with cold, cubed butter, which creates a stable base for the buttercream. It takes a bit of extra whipping to soften it, but it’s worth it. Once you’ve made your frosting, you’ll divide and color it. See my tips below, and refer to the recipe card for detailed instructions.

Frosting Tips and Colors

The frosting can be made up to 7 days in advance and kept refrigerated. It does need to come back to room temperature and be rewhipped before decorating the cake.

Frosting colors get better the longer they sit. For this reason, I recommend coloring the buttercream at least one day before you plan to decorate, especially for the black color. If needed, check out my in-depth tutorial on coloring buttercream for details. Then, dye the frosting for this Gravedigger cake following the coloring guide below. All the colors mentioned here can be found in my favorite 12-pack of gel colors with the exception of electric green, which you can purchase separately.

Green – To achieve the perfect Gravedigger green, I used a combination of electric green gel colors (also similar to Chef Master Neon Green) and just a touch of leaf green to slightly darken it.
Purple – For the purple, I used violet and a touch of black gel to darken it. You can add a little bit of red gel for a deeper purple color.
Black – I recommend adding black cocoa powder to the frosting base to achieve a deep black color with minimal gel colors. It gives the black frosting a chocolatey flavor, but I prefer that over adding heaping amounts of gel color. After you add the cocoa powder, stir in your black gel to achieve the desired color.

Filling the cake: You may not see it at first, but the cake layers are frosted with the chocolate buttercream, which I choose to not dyed black. This means that I needed to dye a much smaller amount of frosting which can be easier to work with.

Leftover buttercream: If it feels like you made a ton of frosting, you’d be correct, but it’s much easier to freeze leftover buttercream then to try and match colors if you come up short.

Close up overhead view of three piping bags filled with purple, green, and black colored frosting.

Cut Out the Fondant

I used precolored fondant to make the black and white checkered flag pattern on the bottom of the cake. You’ll find fondant in craft stores like Michaels or Hobby Lobby, and at Walmart.

Roll out the fondant. I used my fondant roller to roll out both colors to a thin, even thickness (not less than ⅛” or the fondant might tear).
Use a cookie cutter. Next, use a square cookie cutter to cut out ⅝” squares. You’ll need approximately 30 squares of each color, but cut a few extra in case they bend. Initially, I cut squares that were closer to ¾”, but I felt they were a bit too large for the 6-inch cake.
Or use a pizza cutter. Alternatively, you can use a ruler and pizza cutter to measure and cut the squares (I’ve also seen plunger cutters and these multi-cutter squares, but I have not personally used them).

Once you have your fondant cut-outs, set them aside for now (in an airtight container), or you can store them for later. Fondant decorations can be prepared 48 hours in advance and kept in a flat, airtight container until you’re ready to use them.

Overhead view of rolled out black fondant and partially cut-out fondant squares, with a cookie cutter and rolling pin.

Decorate the Cake

After assembling the layer cake and applying a crumb coat, it’s a good idea to chill the cake in the fridge for 15-30 minutes before you decorate it. Then, it’s time to bring this Gravedigger birthday cake to life:

Prepare the piping bags. Next, add your 3 buttercream colors to small piping bags. If needed, check out how to use a piping bag for details.
Pipe the buttercream. Starting at the bottom edge of your assembled layer cake, pipe 3 rows of black buttercream. Then, pipe 2 rows of green, followed by purple buttercream. If you happen to come up short without finishing the row, don’t stress. It’s an ombre effect! Just start the next color right where you left off.

A layer cake frosted with black buttercream on a cake stand. — Start with a layer of black frosting.

Green frosting being piped over a layer of black frosting on a frosted layer cake. — Start with a layer of black frosting.

Smooth it out. Run an icing scraper under very hot water, then wipe it dry. Place the scraper at a 90º angle against the side of the cake, and using light pressure, rotate the cake to smooth out the frosting. Clean the scraper with hot water at the halfway mark and start again until everything is even and smooth. For any frosting along the top edge, just pull it into the middle of the cake since we’re covering that with Oreo crumbs anyway.
Add tire marks. This step is optional, but if you’d like to add tire treads for extra texture, use a Monster Truck toy or similar, place the wheels gently against the sides of the cake, and run the truck lightly through the buttercream. This works best once the buttercream forms a light crust, otherwise, if it’s too soft it will just stick to the tires.
Add the fondant. Next, press the fondant squares around the bottom edge of the cake, alternating black and white to create a checkered pattern.

Julianne’s Tips for Working With Fondant

After doing two different cakes with this fondant checkered pattern, here’s a few things you should know if you’re new to working with it.

Chilling the cake effects the fondant. When the cake comes back to room temperature, you may notice that the fondant looks wet and soft at first. As the cake comes back to room temperature it should reset. If you’re planning to make the cake ahead and freeze it, I would wait to add the fondant until it’s fully thawed.
Attaching the fondant to the cake: You may need to rough up the buttercream underneath with a toothpick if you find that the fondant isn’t sticking to the smoothed cake. Alternatively you can use a toothpick and add some leftover buttercream on the back of the squares or use piping gel. Pro tip: If you have a flat angled spatula, you can press the fondant into the cake to help the square line up a little better.
It’s best within the first couple days. You’ll notice that after a few days, the moisture from the cake may cause the fondant to wilt a bit, which is why I recommend not adding it too early.

An icing scraper being used to smooth out the frosting on a layer cake. — Press an icing scraper against the side of the cake.

A layer cake frosted with smoothed out purple, electric green, and black frosting. — Press an icing scraper against the side of the cake.

Don’t Make This Mistake!

You need to add at least 3 layers of black buttercream on the bottom edge, otherwise it will be fully covered by the fondant checkers and you won’t see any of the black.

Decorate. To the frosted cake, I added a thin layer of chocolate buttercream on top and covered that with Oreo crumbs that I ground up in the food processor (creme filling and all). Then, I topped the cake with a crushable car, my son’s favorite Gravedigger truck, a mini flag topper and edible chocolate boulders. You’ll find the boulders on Amazon, and I also recently found them at Hobby Lobby. Finally, I pressed some leftover fondant into these tire molds as an extra garnish for the cake (these also work great with melted chocolate!).

Monster Jam Birthday Party Decor

Just like I did for my son’s dinosaur birthday cake for his 1st birthday, I tied the decor for his 2nd birthday into this Monster Jam-themed cake. I bought this Monster Truck confetti and these adorable custom logo stickers from sellers on Etsy, and this racing-themed number 2 balloon from Amazon. I did the balloon arch using a couple different bags of ballons I had or purchased, but there’s lots of options available on Amazon.

Then, I strung up this “Two Fast” banner in front of the checkered table cloth, triangle flag banner, and balloons I found at Hobby Lobby. My son’s Monster Truck toys got to wear mini party hats, and I topped his cake with these cute checker candles. It’s safe to say he was thrilled!

I also custom-made the number 2 sign using a cardboard platter (like you’d see for Charcuterie), I purchased it at Hobby Lobby I covered the inside with checkered vinyl (also purchased from Hobby Lobby but there are similar options at Michaels and it may also work with checkered tape, but it would take more work to line up the pattern. I glued down some Monster Jam trucks from Dollar Tree and grabbed a skateboard ramp (also from Dollar Tree) to look like a jump. I am kinda of obsessed with how it turned out.

A full Monster Jam birthday spread with a monster truck cake and decorations on a table, and a balloon arc in the background.

Make-Ahead and Storage

Cake layers. You can bake your cake layers up to 2 days in advance. After they’ve cooled, wrap the cakes tightly in plastic wrap and store them at room temperature. You can also freeze the unfrosted cake layers for up to 1 month.
Store leftover cake. Leftover frosted cake can be kept at room temperature in a cake carrier or tightly covered. I usually only suggest storing frosted cakes in the fridge if you happen to live somewhere hot and humid. Remove any plastic decorations before storing.
Leftover frosting. You can prepare your buttercream frosting up to a week ahead and keep it airtight in the fridge. Bring the frosting to room temperature and re-whip it before you use it. Any leftover buttercream and be frozen for up to 2 months in an airtight container.

More Birthday Cake Ideas