Bath & Beauty Recipes

DIY Unicorn Cupcake Bath Bombs with Whipped Soap Frosting

February 18, 2021

Learn how to make DIY bath bomb cupcakes with soap frosting! These sparkly unicorn cupcakes are super fun for kids and make the water colorful and foamy. The easy homemade bath bomb recipe is made with natural ingredients and essential oils.

Unicorn Cupcake Bath Bombs with Soap Frosting

Since I shared my snickerdoodle soap cupcakes, I received requests to make cupcake bath bombs with soap frosting. So, I decided to combine two of my favorite things, cupcakes and unicorns, and create homemade unicorn cupcake bath bombs.

Not only do these rainbow unicorn bath bombs look magical, but they create heaps of pastel-colored foam and tint the bathwater purple. The cupcake bath bombs also release a delicious scent, and you can find three essential oil blends for bath bombs below.

DIY Cupcake Bath Bombs

How do you make bath bombs look like cupcakes? This DIY cupcake bath bombs recipe consist of two parts: the bath bomb base and a fluffy soap icing on top. I’ll walk you through making the bath bomb mixture, as well as the homemade soap frosting recipe. Let’s started with the bath bombs!

Cupcake Bath Bomb Ingredients

These cupcake bath bombs with icing come together with just a few materials. You can find the exact measurements in the DIY box below.

Baking Soda
Citric Acid
Cocoa Butter – You could also use shea butter or coconut oil.
Polysorbate 80 – Polysorbate 80 is a solubilizer, which is similar to an emulsifier, that helps the cocoa butter, essential oils, and color disperse in the bathwater.
Essential Oils – Check below for some yummy bath bomb blends.

Next, grab these tools:

How to Make DIY Cupcake Bath Bombs

Here are the steps for how to make cupcake bath bombs:

Melt the cocoa butter in a water bath or in the microwave.
Let cool for a few minutes. Then stir in the Polysorbate 80 and essential oils. Set aside.
Combine the baking powder and citric acid in a large mixing bowl. If the ingredients are lumpy, sift them to break up any clumps.
Pour the melted cocoa butter over the dry ingredients and mix.
Put on gloves and knead until the mixture sticks together when pressed and resembles damp sand texture.
Divide the bath bomb mixture into four batches and color three pink, blue, and purple. Add 1-2 teaspoons of mica powder per color.
To form the cupcakes, fill the mixture into the cupcake mold until full, changing the colors as you go. If you want to hide a colorful surprise inside your bath bombs, add one of these rainbow bar embeds.
The next step is important: press and compact the mixture firmly into the mold. And top up with mixture until the mold is filled to the rim. The more packed and denser the mixture is, the better the cupcakes will hold together.
Let the bath bombs harden in the mold. They should be done in 4-6 hours, but the process can take longer if you live in an area with high humidity.
Then carefully release them from the mold.

DIY Soap Frosting Recipe

How do you make soap icing? I wanted to make a quick and easy soap frosting without meringue powder or sugar. Instead, I bought this pre-made foaming bath butter from Stephenson/Mystic Moments. The whipped soap base from Nature’s Garden or the bath whip from Crafter’s Choice are great alternatives.

To make whipped soap from scratch, check out this whipped soap recipe with melt and pour soap from my friend Cari of Everything Pretty.

Soap Icing Ingredients

Here are the ingredients for the DIY whipped soap frosting:

Whipped Soap Base
Pink, Sky Blue, and Purple Mica
up to 70 drops essential oils (optional, see my ideas below)

You also want to assemble the following equipment:

How to Make Soap Frosting

Now that we’ve discussed the ingredients, let’s get to the fun part: how to make whipped soap frosting using a base!

Add the soap base into a large mixing bowl.
Start mixing on low increasing the speed as you go.
Occasionally scratch down the side of the bowl with a rubber spatula so that everything mixes evenly.
Whip the soap base until the mixture has doubled or tripled in volume.
I used a hand-held mixer, but a stand mixer is fine, too.

And there you have it, a big bowl of fluffy whipped soap frosting! Please note that this bath bomb frosting recipe stays soft and doesn’t harden. If you want to make these bath bombs for sale and need a frosting that hardens, try this soap icing recipe.

How to Frost Cupcake Bath Bombs

It’s incredibly satisfying to frost cupcake bath bombs! You’ll need 5 large, disposable piping bags plus a piping tip/nozzle. A large star piping tip will give you the best results. I used the Wilton 1M. The Wilton 2D or Ateco 828 would also work great.

The gorgeous swirl effect is inspired by rainbow buttercream cupcakes. The technique looks fancy but is surprisingly simple to make. Here’s what you do:

Divide the whipped soap frosting between four mixing bowls.
Color three portions with pink, blue, and purple mica, the fourth remains white. Expect to add 1 to 1.5 teaspoons of mica per batch.
Fill each color into a pastry bag.
Cut off the tip of each pastry bag.
Pipe a line of each color right next to each other on a piece of plastic wrap. Then roll up the plastic wrap, folding the colors together. Twist the ends of the plastic wrap together and snip off one end.
Insert the rolled-up frosting into a pastry bag fitted with a star tip/nozzle and twist up the end.
Finally, squeeze the soap icing onto the cupcakes. Holding the piping bag vertically, start in the center of a cupcake and pipe in a circle going outwards. Continue piping in a spiral to build up height.

Decorate DIY Unicorn Bath Bombs

Now that our DIY cupcake bath bombs are assembled, let’s have some fun decorating!

I made cute unicorn horns and ears from soap, and you can do too! Follow these steps:

Melt a little melt and pour soap and pour into a unicorn mold.
Let cool until solid.
Once hardened, pop the soap decorations out of the mold.
Paint the horn with gold mica (FYI, the mica will stick right on the soap) and give the ears a light dusting using a soft brush.
Attaching the horn and ears is as easy as sticking these decorations into the soap icing.
The last step is to sprinkle your DIY cupcake bath bombs with biodegradable glitter for extra sparkles. Yay, you’re done!

Can you put edible sprinkles in bath bombs?

Yes, you can decorate your bath bomb cupcakes with edible sprinkles because sprinkles made from sugar will completely dissolve in water. These unicorn sprinkle mixes would look delightful on the soap icing.

Essential Oil Ideas for Cupcake Bath Bombs

I love creating fragrance blends (just take a look at my perfume ideas) and came up with three yummy and kid-friendly bath bomb scents:

Candy Cupcake: 70 drops cupcake fragrance oil* + 30 drops sweet orange essential oil + 10 drops copaiba essential oil
Pastel Skies: 80 drops Amyris essential oil + 30 drops ho wood essential oils + 20 drops jasmine absolute**
Vanilla Twilight: 90 drops vanilla oleoresin + 35 drops lavender essential oil + 15 drops fir essential oil

*This scent is from a set of dessert-inspired fragrance oil, that I also used to scent these cookie dough bath bombs.

**Jasmine absolute can be expensive to source, but you can simply substitute it with ylang ylang essential oil.

The amounts are enough to scent the bath bomb base. Use half of the amounts to fragrance the soap icing.

How to Use Unicorn Cupcake Bath Bombs

You use the DIY bath bomb cupcakes like you would use any other bath bombs:

First, fill your bathtub with warm water. These bath bombs don’t perform well in cold water, so ensure that the water is at least lukewarm
Then simply toss a bath bomb into the water.
The cupcake base will dissolve and create lots of foam and bubbles in the process. As you can see in the picture, the foam has lovely pastel shades, and the water turns purple.
The soap frosting is going to float on the surface. It’s so much fun to stir it into the water or use it to wash your body.

Since these unicorn bath bombs contain cocoa butter and a lot of mica, they can leave a ring around the bathtub (despite using Poly 80). You can easily remove the ring with my DIY shower cleaner. But don’t worry, they won’t stain your tub.

Storage instructions

Store the DIY unicorn bath bombs in an airtight container in a dry place. They will last around 4-6 months.

As mentioned, the soap frosting made with bath whip doesn’t harden but stays soft. So be careful when you package and store your iced cupcake bath bombs.

Yield: 6 bath bomb cupcakes

DIY Bath Bomb Cupcakes Recipe + Instructions

Learn how to make this DIY bath bomb cupcakes recipe with soap frosting! These sparkly unicorn cupcakes create colorful foaming bubbles for bath time fun for kids and adults alike.

Active Time 2 hours

Additional Time 6 hours

Total Time 8 hours

Difficulty Intermediate

Materials

Cupcake Bath Bombs

2 cups / 260 g / 9.2 oz baking soda
1 1/4 cups / 125 g / 4.4 oz citric acid
1/3 cup (melted) / 65 g / 2.3 oz cocoa butter (can sub for shea butter or coconut oil)
1 tbsp / 15 g / 0.5 oz Polysorbate 80
up to 140 drops essential oils (see blends below)
1-2 tsp baby pink mica powder
1-2 tsp sky blue mica powder
1-2 tsp purple mica powder

Soap Frosting

1 1/2 cups / 340 g / 12 oz whipped soap base 1 tsp baby pink mica powder
1 tsp sky blue mica powder
1 tsp purple mica powder
30 drops essential oils (optional, see blends below)

Decorations (optional)

30 g / 1 oz white melt and pour soap gold mica powder
biodegradable glitter

Tools

Bath Bombs

large mixing bowl sieve (optional)
spoon or whisk silicone cupcake mold nitrile gloves (optional)

Soap Icing

small + large mixing bowls
hand-held or stand mixer rubber spatula

Decorations

heat-proof glass measuring cup unicorn silicone mold
soft brush

Instructions

Make the bath bombs

Melt the cocoa butter in a water bath or in the microwave.

Let cool for a few minutes. Then stir in the Polysorbate 80 and essential oils. Set aside.

Combine the baking powder and citric acid in a large mixing bowl. If the ingredients are lumpy, sift them to break up any clumps.

Pour the melted cocoa butter over the dry ingredients and mix.

Put on gloves and knead until the mixture sticks together when pressed and resembles damp sand texture.

Divide the bath bomb mixture into four batches and color three pink, blue, and purple. Add 1-2 teaspoons of powder per color.

To form the cupcakes, fill the mixture into the cupcake mold until full, changing the colors as you go. If you want to hide a colorful surprise inside your bath bombs, add one of these rainbow bar embeds. The next step is important: press and compact the mixture firmly into the mold. And top up with mixture until the mold is filled to the rim. The more packed and denser the mixture is, the better the cupcakes will hold together.

Let the bath bombs harden in the mold. They should be done in 4-6 hours, but the process can take longer if you live in an area with high humidity.

Carefully release them from the mold.

Whip the soap frosting

Add the soap base into a large mixing bowl.

Start mixing on low increasing the speed as you go.

Occasionally scratch down the side of the bowl with a rubber spatula so that everything mixes evenly.

Whip the soap base until the mixture has doubled or tripled in volume.

I used a hand-held mixer, but a stand mixer is fine, too.

Frost the bath bomb cupcakes

Divide the whipped soap frosting between four mixing bowls.

Color three portions with pink, blue, and purple mica, the fourth remains white. Expect to add 1 to 1.5 teaspoons of mica per batch.

Fill each color into a pastry bag.Cut off the tip of each pastry bag.

Pipe a line of each color right next to each other on a piece of plastic wrap. Then roll up the plastic wrap, folding the colors together. Twist the ends of the plastic wrap together and snip off one end. Insert the rolled-up frosting into a pastry bag fitted with a star tip/nozzle and twist up the end.

Finally, squeeze the soap icing onto the cupcakes. Holding the piping bag vertically, start in the center of a cupcake and pipe in a circle going outwards. Continue piping in a spiral to build up height.

Make soap unicorn horns and ears

Melt the 30 g / 1-oz melt and pour soap in the microwave or a water bath. Pour into a unicorn mold.Let cool until solid.

Once hardened, pop the soap decorations out of the mold.

Paint the horn with gold mica and give the ears a light dusting. The mica will stick right on the soap.

Decorate the cupcake bath bombs

Place the unicorn horn in the middle of the soap icing tuff and place the unicorn ears next to it. Sprinkle the DIY cupcake bath bombs with biodegradable glitter.

Notes

Bath Bomb Essential Oil Blends