Tutorial: Birthday Cake Loaf Soap

Nothing says “Happy Birthday” like rainbow sprinkles, and these colorful jojoba beads are a perfect stand-in. For a soap design this sweet, Bramble Berry’s new “Hello Sweet Thang” or Cream Cheese Frosting fragrance oil makes every day a party!

What you’ll need:

3 lbs. White Melt & Pour Soap Base
Hydrated Chrome Green Oxide
Pink Oxide
Hello Sweet Thang fragrance oil
Jojoba Beads in Red, Purple, and Blue
Loaf Mold
Small mixing cup
Metal 1/2 t. measuring spoon or small melon baller
Optional: Vanilla Color Stabilizer

In a small cup, combine 1/4 teaspoon of each color Jojoba Beads. Set aside.

In a 2 cup Pyrex, melt 12 ounces of white soap base. Using a small cup, spray a few squirts of rubbing alcohol and stir in 1/8 teaspoon pink oxide. Stir until all lumps are gone and add to the soap base. Add 1/2 teaspoon of fragrance oil and pour into soap mold. If you are using Vanilla Color Stabilizer to decrease the natural browning effect of the Vanilla in the fragrance, combine it with the fragrance every time fragrance is called for at a 1:1 ratio. Allow to set until surface is solid but still warm and you can push a dent into the soap with your finger.

Take your teaspoon and scoop 3 long grooves out of the soap, like you’re scooping ice cream. Make them about 1/4″ deep, then use your finger to round off any hard edges (you want smooth curves when you slice into the soap).

Melt 8 ounces of white soap. Let cool to 120 degrees. Spray surface of pink soap with rubbing alcohol and pour soap into mold. When soap is set but scoopable, make 3 more grooves like you did in the last step.

Melt 12 ounces of white soap. Dilute 1/8 teaspoon of hydrated green oxide in a few sprays of rubbing alcohol and add to soap. Stir in 1/2 teaspoon of fragrance oil. Let cool to 120 degrees, spray white soap layer with alcohol, and pour green soap into mold. Let cool until solid.

Melt 10 ounces of white soap. Let cool to 120 degrees and stir in 1/8 teaspoon of Jojoba Beads. Stir until soap is thick and beads stop floating. Spray green soap with alcohol and pour soap into mold.

To create a frosting effect, use a spoon to push melted soap back and forth. Keep pushing as it starts solidifying, creating a frosting texture. Push and push until you like the texture or it’s too thick to move anymore. Sprinkle more Jojoba Beads on top.

Let soap completely solidify. You can let it sit overnight or put in the freezer for 20 minutes. Unmold and slice with an unserrated knife.

These soaps would make excellent favors for your next birthday party!


For more information and tips on how to use oxide colorants, come back on Thursday for a full post about these great skin safe and colorfast pigments!


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  1. Corrine dirks says

    Where to buy mold? And what model number. There are so many. Cute soap can hardly wait to try.

  2. Spyou says

    Just find you blog and your photos while preparing my top 10 soap inspiration post.

    Your creations are amazing. Thanks you very much for sharing.

    Nic from blog.serialcooking.com

  3. Michelle says

    Fantastic! I love the pastel colors and sprinkles. Thank you for sharing the wonderful idea :)

  4. Amy says

    Wow.. I just realized that in the last photo, my sister has the exact same spoon…crazy! The the soap looks yummy, by the way. I would probably try to eat it.

  5. Anne-Marie says

    Anon, The Hello Sweet Thang probably will discolor. There is Vanilla in it. But you can use the Vanilla Color Stabilizer Bramble Berry sells if you’re making melt and pour to keep your soap nice and white =)

  6. Cakespy says

    The most delicious-looking soap I’ve ever seen! I wish I could smell it, it sounds incredible!

  7. Anonymous says

    Debbie you are so very creative!
    Thank you for such easy to follow instructions. Now I must order a loaf mold.
    PS. Does the “Hello sweet thang” fo discolor?

  8. Eat Well (was Teresa R) says

    Now I wish I’d bought the mold when I bought the seashells kit…dang…oh well, next time. It’s such a cool “cake”!

  9. Armi says

    I was wondering how you got those grooves in the soap loaf when I saw the picture on your blog, Debbie! Well, now I know. Another superb tutorial – really clear, easy to follow directions. Now I want that loaf mold and the newest fragrances from BB too.

  10. Heavenly Scent Soaps says

    VERY CUTE!! I can’t wait to order the new BB fragrances. They sound yummy!!

    Thanks for the great tutorial!

    Kind Regards,

  11. jennifer says

    Oh wow, that scent sounds awesome! Can you suggest a similar scent that doesn’t color that you can ship to Canada? I was all set to order, and saw the disclaimer. *sniff*

  12. Colleen says

    Another great tutorial! The soap loaf looks good enough to eat. Thanks for the great directions!