I’ve continued my animal cake series with my favorite animal…a hippo cake! In my opinion, hippos are the true king of the jungle.

They are amazing for many reasons, but my favorite is that they secrete a fluid from their skin that acts as a sunscreen, helps them regulate their temperature, and gives them a somewhat purplish hue.

To make this adorable hippo cake, I used a purple vanilla cake base and purple and blue buttercream! I wanted him to look like he was just peeking his head up out of the water.

Making this Hippo Cake: Step by Step Tutorial

Let’s walk through each step of this cake together to make sure it turns out as amazing as possible!

Step 1: Make the Purple Cake Batter

After making your cake layers, add in purple gel food coloring and stir by hand with a rubber spatula until the batter is evenly colored.

Fill the 4-inch cake pans about 1-inch high with batter, then use the remaining batter to fill the domed cake pan.

I ended up baking an extra 4-inch cake layer in the photo below, but found during recipe testing that this cake turns out best when made with three, 4-inch cake layers.

Step 2: Bake and Trim Your Cake Layers

Bake the 4-inch cake layers for 25-30 minutes, or until a toothpick comes out with a few moist crumbs. Bake the domed cake pan for 40-50 minutes, or until a toothpick comes out with a few moist crumbs.

Allow the pans to cool for 20 minutes, then run a small offset spatula around perimeter of the pan to separate the cake from the pan and flip the layers onto a wire rack to finish cooling.

Use a sharp knife to cut out a semi-circle from the side of the domed cake layer that is roughly the same size as the 4-inch cake layers. Then use a serrated knife to level the tops of the 4-inch cake layers and cut the domed cake layer into thinner layers. Set aside.

Step 3: Make the Buttercream Frosting

While the cake layers bake and cool, make the vanilla buttercream frosting with either an electric hand mixer or a stand mixer.

If your frosting seems too thick after mixing together all your ingredients, add in additional cream (1 teaspoon at a time). Or if the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).

If you’re unsure how thick your frosting should be, you can learn what consistency you’re looking for in my frosting consistency post.

I like to wait to color the buttercream purple until the cake is crumb coated. Filling the cake with white buttercream really helps the color of the cake layers pop.

Step 4: Assemble and Crumb Coat the Cake Layers

Stack and frost cake layers on a 10-inch greaseproof cake board using a dab of frosting to help stick the bottom cake layer to the board.

Spread an even layer of buttercream between each cake layer with a small offset spatula. Add a thin coat of frosting around the the cake to fully cover the cake layers.

Smooth using a bench scraper or a small acetate sheet, then chill the cake in the fridge (20 minutes) or freezer (10 minutes) until the frosting is firm to the touch.

Step 5: Color Your Buttercream & Frost the Chilled Cake

While the cake chills, color about 1 cup of the uncolored buttercream blue with gel food coloring. Cover and set aside. Color the remaining buttercream purple with purple gel food coloring.

Once the crumb coat is firm to the touch, add a second, thicker layer of purple frosting around the chilled cake and smooth using a small acetate sheet or small offset spatula.

Step 6: Making this Little Hippo’s Face

The next step is to add on the hippo’s face! This can be done with buttercream or fondant.

I’ve made this cake twice and the first time I used fondant to make the face. The upside of using fondant is that it is faster and easier for anyone who isn’t super comfortable piping buttercream. The downside is you need three colors of fondant and fondant tools to cut the shapes.

I recommend using small circle cutters to get the shape of the ears and eyes just right.

The second time I made this hippo cake I used buttercream to make the face. It was easy because I always have leftover white and black buttercream frosting in piping bags in my fridge from past projects. I also feel pretty comfortable piping!

Either method will work, and I recommend doing whatever you feel the most comfortable with.

Step 7: Cover the Board with Blue Buttercream

The final step is to cover your cake board with blue buttercream to look like waves. We want this hippo to look like it’s just peeking his head out of water to say hi, and the blue buttercream totally completes this look!

Substitutions and Swaps – Vanilla Cake Layers

This hippo birthday cake uses quite a few ingredients and I know you might not have all of them on hand. Or if you have food allergies or restrictions, I’ve got you covered.

Below are some swaps and substitutions that can be made in this cake recipe.

• All Purpose Flour – This recipe turns out best with AP flour, but you can use a gluten free flour blend or cake flour if that’s all you have on hand. I don’t recommend using straight almond flour though!
• Granulated Sugar – I do not recommend reducing the amount of sugar or changing the type of sugar, as it will change the texture of the cake layers.
• Unsalted Butter – If you only have salted butter on hand you can use it in place of the unsalted butter in this recipe. Just be sure to omit the salt that this cake recipe calls for. You can also use vegan butter in its place!
• Egg whites – You can use 3 whole eggs in place of the egg whites in this recipe if needed. Or if you have an egg allergy you can use flaxseed eggs or an egg replacer.
• Buttermilk – You can also use full fat yogurt, sour cream, whole milk, or an alternative yogurt or milk (almond, soy, oat) if you’re dairy free.
• Vegetable Oil – You can use any flavorless oil in this recipe. Canola or even sunflower oil would work great!
• Vanilla Extract – Other extracts can also be used in place of the vanilla extract. Feel free to use almond, lemon, or even coconut extract.
• Gel food coloring – Natural food coloring (either liquid or powder) or liquid food coloring can be used if needed.

Substitutions and Swaps – Vanilla Buttercream Frosting

• Unsalted Butter – If you only have salted butter on hand you can use it in place of the unsalted butter. Just be sure to omit the salt that this frosting recipe calls for. You can also use vegan butter in its place!
• Heavy Cream – Whole milk or alternative milk (soy, almond, oat) will work fine in this frosting recipe if that’s what you have on hand.
• Vanilla Extract – Other extracts can also be used in place of the vanilla extract. Feel free to use coconut extract, hazelnut extract, or even pistachio extract.
• Gel food coloring – Natural food coloring (either liquid or powder) or liquid food coloring can be used if needed.

Tips for Making the Best Hippo Cake:

• Be sure to properly measure your flour (spoon into the cup measure then level) or use a kitchen scale to measure your dry ingredients.
• Use gel food coloring to create brightly colored frosting without throwing off the consistency of the frosting or giving it a bitter taste.
• Ingredients at room temp mix together better, so be sure you set out any cold ingredients ahead of time.
• Mix your cake batter just until the ingredients are incorporated. This will ensure your cake layers are tender and soft.
• Use an acetate sheet to help you get your final coat of frosting super smooth.
• Chill your cake layers in the freezer for about 20 minutes before assembling the cake. This makes it easier to stack and frost.
• Make this hippo cake vegan or dairy free if needed! Use your favorite type of dairy free milk to replace the buttermilk and heavy cream, and use vegan butter sticks in place of the butter. For the eggs I recommend using an egg replacer like this.
• If you want to make a standard / non-sculpted hippo layer cake, you can bake 3, 6-inch cake layers and add the same fondant features.

Making this Hippo Cake in Advance & Storage Tips:

• Make your cake layers in advance and freeze them. It breaks the process up and make it more approachable.
• Make your frosting ahead of time too or save any leftover frosting. It can be stored in an airtight container in the fridge for up to a month. Or store it in the freezer for up to 3 months! Be sure to give it a good stir once it thaws to get the consistency smooth again.
• A frosted cake can last in the fridge for up to a week. The buttercream locks in all the moisture, keeping the cake fresh and delicious.
• If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist. It can be stored in the fridge like this for up to a week.

Let Me Know What You Think!

If you try this hippo birthday cake recipe, I’d love to hear what you think of it! Let me know by leaving a rating below.

If you plan to share on social media, you can tag me @chelsweets! Also use the #chelsweets so that I can see your amazing creations on social media.

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For a walk down memory lane, here is the original version of my hippo cake from 2016.