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How to Make a Fondant Covered T-Rex Cake

Lisa's hobby of making fun cakes for family and friends started 13 years ago when she discovered Food Network.

T-Rex Birthday Cake

how-to-make-a-t-rex-cake

Every year, about a month before my kids’ birthdays, I ask them what kind of cake they want, and start planning out how to pull it off.

For my son’s 7th birthday, he asked for a T-Rex cake. At the time it was the most ambitious cake I had made, and it turned out to be one of the most fun. Decorating a cake to look like a T-Rex may seem daunting, but if you go step by step, it really just takes time and patience.

Ingredients and Equipment Needed

  • 6 boxes cake mix, prepared
  • 6 cups buttercream frosting, prepared
  • small package of pre-made gum paste, or powder mix
  • small package fondant, black and white
  • 2 lbs chocolate fondant, (My favorite is Duff Goldman's brand, because it tastes like Tootsie Rolls.)
  • vodka or water, for painting
  • 3 cups powdered sugar, for dusting work surface and rolling pin
  • 0.5 oz jars gel food coloring, black, brown, green
  • 10 round cake pan, greased and floured
  • 1 bread knife, for carving
  • 1 avocado knife, for carving (optional)
  • 1 soft brush, for crumbs and excess powdered sugar
  • 6 - 9 lollipop sticks or wooden skewers, cut to size
  • 2 circle fondant/cookie cutter, for cutting out the eyes
  • 1 circle fondant/cookie cutter, for cutting out the eyes
  • large rolling pin, for fondant
  • 20 fondant impression mat, cobblestone
  • 1 box nitrile exam gloves, to protect cake from hands
  • 3 small bowls, for mixing paint
  • 2 angled frosting spatulas, large and small
  • set small paint brushes, synthetic brushes are best
  • 1 box toothpicks, for mixing gel colors and for teeth
  • 1 rounded fondant tool, optional
  • 1 sharp knife, for cutting excess fondant

Basic Instructions

  1. Plan out what you want your cake to look like.
  2. Bake and stack the cakes.
  3. Carve the cake into the shape of a t-rex.
  4. Apply crumb coating.
  5. Create gum paste ridges.
  6. Create eyes.
  7. Cover the cake in fondant.
  8. Hand-paint the details.
  9. Make the teeth.

Step 1: Planning

The first step in making this cake was to find a reference. I searched online for other cakes that were similar in theme, and started deciding what I liked, and didn't like about them. Then I decided if I wanted to make a regular square or round cake with themed decorations on top, or a sculpted cake.

For this T-Rex cake, I decided to make it a 3D head. I wasn’t ready to commit to the entire body. I printed off a few pictures of t-rex heads from different angles and sketched out what I wanted the cake to look like on a piece of paper.

For this guide I'm not going to go into baking the cake, decorating is the main focus.

Step 2: Bake and Stack

After I have a pretty good idea of what I want the cake to look like, I decide which pan shapes and sizes will come the closest to the finished shape. For this cake, I chose a 10" x 3" round cake pan and baked 6 boxes of cake. I know that seems like a ton. This cake was huge, so feel free to cut it down. I always make much larger cakes than I think I’m going to need. That way if I mess up I’ll have extra and won't have to stop everything to start baking again.

You'll need:

  • 10" x 3" round cake pan
  • buttercream frosting
  • spatula

1. Bake the cakes, let them cool completely.

2. Level, stack, and fill the cake with buttercream frosting, or whatever filling you prefer. I use stiff buttercream because it holds up well under heavy cakes.

Leveled, filled, and stacked.

Leveled, filled, and stacked.

Step 3: Carving a T-Rex

You'll Need:

  • bread knife
  • avocado knife (optional)

1. Focus on the basic shape of the outer edges of the cake. Use a serrated bread knife and gentle sawing motions.

2. Using reference photos, start carving the basic shapes of the ridges on top of the head and the eye sockets. I happened to have a curved avocado knife laying around, so I used that to make the curves a little easier, but you don’t need one.

3. Round off the sharper edges of the back of the head and sides.

4. Carve the mouth. I only carved about an inch and a half deep, to maintain the structure. I didn’t want the mouth to start closing!

Eye sockets and ridges carved out.

Eye sockets and ridges carved out.

Mouth carved and edges rounded.  So many crumbs!

Mouth carved and edges rounded. So many crumbs!

Step 4: Crumb Coating

You'll need:

  • soft brush
  • spatula
  • buttercream frosting

1. Apply a thin layer of buttercream to seal in all the crumbs. This can be a tricky step on a regular cake with a flat top, so be patient and try to make it as thin a layer as possible.

2. Transfer to a cake plate. Refrigerate to set the frosting.

Crumb coating applied.

Crumb coating applied.

Step 5: Gum Paste Ridges

You'll need:

  • gum paste
  • lollipop sticks

1. Once the crumb coating has set, use gum paste to form sharper ridges around the eyes and in the center of the head.

2. Push 2-3 lollipop sticks into the base of the gum paste. These will act as anchors so the ridges don't tip to one side or fall off.

3. Push ridges down into place.

It's starting to look like a T-Rex face.

It's starting to look like a T-Rex face.

Step 6: Eyes

You'll need:

  • white fondant
  • black fondant
  • chocolate fondant
  • rolling pin
  • powdered sugar (for dusting the work surface and rolling pin)
  • 2" circle fondant/cookie cutter
  • 1" circle fondant/cookie cutter

1. Roll out a small amount of white, black, and brown fondant. Use circular cookie/fondant cutters to cut two 2” diameter white circles, two 1” brown circles, and two smaller black slits for the pupils.

2. Stack brown iris on top of the white, then the black pupil in the center. When attaching fondant to another piece of fondant, you want to use a tiny bit of water.

3. Dip a tiny paintbrush in water and then press it against the side of the bowl. You don’t want an entire drop of water touching your fondant. It’ll turn into a slippery gooey mess.

4. Position the eyes on the cake, adhering them with a tiny bit of buttercream.

how-to-make-a-t-rex-cake

Step 7: Covering With Fondant

You'll need:

  • chocolate fondant
  • powdered sugar (for dusting the work surface and rolling pin)
  • rolling pin
  • fondant impression mat
  • sharp knife
  • nitrile exam gloves (optional)

Working with fondant can be tricky. It needs to be rolled out to about a 1/8” thickness with a rolling pin dusted with powdered sugar. If it’s too thin, it will crack, and as it dries it cracks. So you need to work fairly quickly.

1. Knead the fondant. Store-bought fondant is hard when you take it out of the package. If it’s too hard to get out of the container, microwave it for 30 seconds on low to help it soften. Note: If you buy Wilton brand the packages cannot be microwaved as they have metal in them. You really just need the warmth of your hands to soften it.

2. Once the fondant is soft and pliable it's ready to be rolled out. For this cake, the fondant needs to be rolled onto a fondant impression mat to give the skin texture. I used a cobblestone one, because it was the closest thing I could find to dinosaur scales. Make sure you dust the impression mat with powdered sugar so it doesn’t stick. It might take a few times of rolling it out to get it right.

3. Gently drape the fondant over the cake, allowing the fondant to fall in-between the ridges.

4. Use your hands to gently start molding the fondant to the cake, stretching it slightly as you go. If you stretch it too much it’ll crack, or distort the impression, so be gentle. Be sure to keep the fondant right up against the cake, pressing it into the mouth area to create a depression. I like to use nitrile exam gloves during this step so the moisture from my hands doesn't affect the cake.

5. Use a sharp knife to cut away the excess fondant, and create a clean bottom edge.

6. Use your fingers to feel where the eye is laying under the skin, and carefully slice through the top layer of fondant to create a slit. Gently push the fondant apart, with a rounded fondant tool, or a spoon, to create the eyelids.

7. Add black fondant to fit the shape of the mouth, and adhere with a small amount of water.

I kept the fondant wrinkled on the side to look more like skin.

I kept the fondant wrinkled on the side to look more like skin.

The wrinkled fondant makes the mouth look more realistic as well.

The wrinkled fondant makes the mouth look more realistic as well.

Step 8: Hand Painting the Cake

You'll Need:

  • 3 small bowls
  • vodka or water
  • gel food coloring (black, brown, green)
  • small paint brushes

1. Mix gel food coloring and vodka. I use vodka because it evaporates faster than water, and doesn’t make the fondant as gummy as easily. There’s not a ratio of color to vodka that I use, I just want the color to be intense, but thin enough to paint.

2. Start painting, staying as close to the reference photos as possible. Layering the colors on top of, and around each other, creates more depth and looks more natural.

Black fondant added to mouth and eye painted.

Black fondant added to mouth and eye painted.

Top view.

Top view.

Step 9: T-Rex Teeth

The teeth of this cake crack me up. I started making small pointy teeth on toothpicks to slide into the mouth, but my son was not happy with the size. “They’ve got to be bigger!” So I angled larger teeth out and made this dinosaur a bit of a snaggletooth.

You'll Need:

  • gum paste
  • toothpicks

1. Form teeth shapes on toothpicks.

2. Let dry.

3. Push them into the cake.

You can see where I painted around the mouth to create depth.

You can see where I painted around the mouth to create depth.

Finished Cake

This cake took me about 10 hours to make, including baking and carving time. I always do the baking, and sometimes carving, the night before and then decorate it the next day. Making cakes like this is time-consuming and sort of exhausting, but seeing the excitement on the party-goers faces makes it totally worth it.

The final product.

The final product.

A side view of the details.

A side view of the details.

Comments

Linda Crampton from British Columbia, Canada on May 15, 2018:

The cake looks amazing! The first photo is a dramatic beginning to the article and the photos showing the gradual appearance of the dinosaur's face are very interesting. Thanks for sharing all the instructions. I think they'll be very useful for people who like cake decorating and want to create something different from the usual designs.

Paula on May 14, 2018:

What an exciting idea! All kids LOVE dinosaurs and this cake would be the life of the party! Thanks for your explicit step-by-step instructions and photos. My son’s birthday is next month, so I’m going to try to make one for him!